The most rule-governed question type on the SAT (11.2% of the bank). Covers the complete-sentence test that decides every punctuation question, the comma splice and its four legal repairs, colons and dashes and what must precede them, non-essential elements fenced by matched pairs, and the commas that are never legal — with six worked examples, four traps and three checks.
Subject: SAT Prep · 61 slides · applied lesson
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Title
SAT Reading & Writing · Type 5 of 10
11.2% of the question bank — 189 of 1688 questions
Objectives
Four choices that differ only in punctuation, and a sentence that reads identically whichever you pick. There is no judgement in this type and no ear involved. One question, asked about each side of the punctuation, decides every question: is this a complete sentence?
One question decides the whole type: is what comes before it a complete sentence, and is what comes after it one too?
Naruhodo Tutoring — SAT Reading and Writing question bank export (sat-english-question-index.json) — 189 tagged questions of this type in the site's bank
Section
Section 1
Concept
Four choices that differ only in punctuation, and a sentence that reads identically whichever you pick. There is no judgement in this type and no ear involved. One question, asked about each side of the punctuation, decides every question: is this a complete sentence?
You will see it phrased in these ways:
The tell is unmistakable: read the four choices and if the WORDS are identical and only the marks differ, you are in this type.
Picture it
The same three-panel card as the survey deck, so the shorthand carries over: what identifies it, what you write first, and what is built to catch you.
Figure (svg): Boundaries: the tell, the move, and the trap
The red panel names a choice that can be eliminated on structure alone, without reading the sentence for meaning at all. That is unusual and it is worth exploiting.
Prediction
Everything in this type depends on this one definition.
Predict first
Which of these is a complete sentence?
Correct: The samples were ruined
Why: A complete sentence needs a subject and a verb and must be able to stand alone. The samples were ruined has both and stands alone. The other three all have subjects and verbs of a sort, and each is opened by a word — because, which — or a form — ruining — that makes it depend on something else. Because, although, which, when and while all turn a complete sentence into a fragment.
Concept
Three shapes, one test.
| variant | what the choices vary | the question to ask |
|---|---|---|
| Joining two clauses | period, semicolon, comma, colon | is each side a complete sentence? |
| A non-essential element | commas, dashes, parentheses, or none | does the sentence still stand if you delete it? |
| Introducing something | colon, dash, comma, or nothing | is what precedes it a complete sentence? |
All three reduce to the same test applied at a different place. There is genuinely only one rule in this type.
Definition probe
The single most important classification in the type.
Sort into buckets
Is each of these a complete sentence?
Discrimination
Six joins between two complete sentences.
Sort into buckets
Is the punctuation legal?
Warm-up
Two questions, one answer.
Discussion prompt
"The lab closed early ___ the samples were ruined." Which punctuation is legal: a comma, a semicolon, or nothing?
Hint: Ask the question about each side separately.
Answer:
Is what comes before it a complete sentence? The lab closed early — subject, verb, stands alone. Yes.
Is what comes after it a complete sentence? The samples were ruined — subject, verb, stands alone. Yes.
Both complete, so the legal joins are: a period, a semicolon, a comma plus a FANBOYS word, or a colon.
So the semicolon works and the bare comma does not. A comma alone is the comma splice, and it is never legal between two complete sentences.
Nothing at all would be a run-on, which is equally illegal. Two questions settled it, and neither required reading the sentence for meaning.
Pattern
Two questions and a lookup. This is the most mechanical routine on the test.
Cover everything after the punctuation and ask: is what remains a complete sentence?
Why: A complete sentence has a subject and a verb and stands alone. Words such as because, although and which at the front make it a fragment.
Cover everything before the punctuation and ask the same question of the other side.
Why: Both answers are needed, because the legal marks depend on the combination rather than on either side alone.
Look up the combination: both complete, first only, or neither.
Why: Each combination permits a specific set of marks, and the choices can then be filtered mechanically.
Nowhere in this routine do you read the sentence for meaning or say it aloud. That is deliberate — punctuation is inaudible, and the ear cannot help.
Section
Section 2
Concept
Everything in this type depends on being able to classify a stretch of words as complete or not.
| stretch | complete? | why |
|---|---|---|
| The lab closed early | yes | subject and verb, stands alone |
| When the lab closed early | no | when makes it dependent |
| Because the samples were ruined | no | because makes it dependent |
| Ruined by the heat | no | no subject; a participial phrase |
| The samples, which were ruined | no | which opens a dependent clause |
Practise this classification on its own until it is instant. Every other rule in the type is a lookup once you have the two answers.
Concept
When both sides are complete, exactly four joins are available.
| join | example | note |
|---|---|---|
| A period | The trail was icy. We turned back. | always available |
| A semicolon | The trail was icy; we turned back. | signals a close relationship |
| A comma plus FANBOYS | The trail was icy, so we turned back. | the conjunction is required |
| A colon | The trail was icy: we turned back. | only when the second explains the first |
A comma alone is not on the list, and neither is a comma plus however or therefore. Both are illegal joins.
Prediction
Run the test on each side.
Predict first
"The equipment arrived late ___ the experiment began on schedule." Which is legal?
Correct: , but
Why: Both sides are complete sentences, so the legal joins are a period, a semicolon, a colon, or a comma plus a FANBOYS word. But is one of the seven, so comma-but works. A bare comma is a splice. A semicolon followed by a comma is not a construction at all. And a bare and with no comma is not among the standard legal joins when both clauses are full sentences.
Concept
A bare comma cannot join two complete sentences, and the SAT offers one on almost every question.
Recognising a splice lets you eliminate a choice in about two seconds without reading it for sense.
Prediction
Only the left side matters.
Predict first
Which sentence uses the colon correctly?
Correct: The recipe needs three things: flour, eggs and salt
Why: Cover everything from the colon onward. The recipe needs three things stands alone as a complete sentence, so the colon is legal. The ingredients are does not stand alone, nor does the recipe needs, nor does for the recipe. A colon cares only about what precedes it, and in three of the four choices that is a fragment.
Concept
Words such as however, therefore and moreover are not conjunctions, so they need a semicolon before and a comma after.
This is the single most common near-miss on the type: the semicolon is right and the following comma is missing.
Concept
Whatever precedes a colon must stand alone; what follows may be anything.
The rule cares only about the LEFT side. A list, a phrase or a full sentence may all follow a colon legally.
Prediction
Two marks of the same kind.
Predict first
Which sentence punctuates the interruption correctly?
Correct: The report, which ran to 300 pages, was never read
Why: The interrupting clause needs a matched pair, and only the first choice has two commas. The second and fourth mix a comma with a dash, which is never legal. The third has only a closing comma, which leaves a single comma standing between the subject and its verb. Deleting the fenced material leaves the report was never read, confirming it was non-essential.
Concept
Interrupting material is fenced by two commas, two dashes or two parentheses — never a mixture.
If deleting the material breaks the sentence or changes its meaning, the material is essential and takes no punctuation at all.
Concept
A single comma between a subject and its verb is illegal, however long the subject is.
This is why long subjects attract wrong answers: the length makes a pause feel natural, and a pause is not a rule.
Prediction
The comma after is required.
Predict first
Which is correct?
Correct: The data were incomplete; however, the team published
Why: The pattern is semicolon, transition word, comma. The second choice uses commas on both sides, which makes it a splice with however dropped in — however is not a conjunction and cannot join clauses. The third omits the comma after however. The fourth omits the semicolon entirely, leaving a run-on.
Two truths and a lie
Three of these punctuation statements are correct. The one left standing is false.
Eliminate the wrong options
Which statement is FALSE?
Survives elimination: c
Why: However is not a coordinating conjunction, so a comma before it cannot join two complete sentences — that construction is a comma splice with a word inserted. Only the seven FANBOYS words can follow a comma in that role. The correct punctuation with however is a semicolon before it and a comma after it. This near-miss is offered on a large share of Boundaries questions.
Check
Test each side, then look up the combination.
Check your understanding
"The volcano had been dormant for centuries ___ geologists still monitored it closely." Which choice conforms to Standard English?
Answer: A
Why: Both sides are complete sentences. A comma plus a FANBOYS word is one of the four legal joins, and but is one of the seven — and it fits the contrast between dormancy and continued monitoring.
Three of the four are illegal joins, and all three were eliminated by the completeness test alone. Meaning only chose between but and the alternatives once structure had done its work.
Section
Section 3
Worked example
"The samples degraded overnight ___ the entire batch had to be discarded." Choose from: a comma, a semicolon, a comma plus so, or nothing.
Figure (svg): Two clauses, each judged a complete sentence
Cover the right side: the samples degraded overnight. Subject, verb, stands alone. Complete.
Why: The first half of the test.
Cover the left side: the entire batch had to be discarded. Also complete.
Why: The second half. Both answers are needed before looking anything up.
Both complete, so a semicolon and a comma-plus-so are both legal; a bare comma and nothing are not.
Why: Four legal joins, and the two illegal options are the splice and the run-on.
When two legal joins are both offered, the meaning decides. A semicolon signals close relation and comma-plus-so signals consequence explicitly.
Verify: check the meaning fits the chosen join: so signals consequence, and the discarding follows from the degradation.
Why: When several joins are legal, meaning picks between them — but only after structure has narrowed the field.
Answer: a semicolon, or a comma plus so — but never a bare comma
Worked example
"The trail was icy, we turned back at the ridge." What is wrong, and how many ways can it be fixed?
Figure (svg): Two complete clauses joined by a bare comma
Test both sides: the trail was icy is complete, and we turned back at the ridge is complete.
Why: Two complete sentences are being joined.
A bare comma is not among the four legal joins, so this is a comma splice.
Why: The comma is too weak to join two independent clauses.
The four repairs: a period, a semicolon, a comma plus so, or a colon.
Why: Each of the four legal joins fixes it, and the choice between them is a matter of meaning.
Recognising a splice is worth practising on its own, because it eliminates a choice in two seconds without reading for meaning.
Verify: check each repair reads correctly: the trail was icy. We turned back. And the trail was icy; we turned back. Both work.
Why: All four repairs produce grammatical sentences, confirming the diagnosis.
Answer: it is a comma splice, repairable four ways
Worked example
"The team faced three obstacles ___ funding, weather and permissions." Is a colon legal here?
Figure (svg): A complete clause on the left and a list on the right
Cover everything from the punctuation onward: the team faced three obstacles.
Why: This is the colon test — only the left side matters.
That stands alone as a complete sentence, so the colon is legal.
Why: A colon requires a complete sentence to its left and nothing in particular to its right.
The list that follows needs no clause status at all.
Why: Lists, phrases and full sentences may all follow a colon.
The commonest colon error is placing one after a phrase such as the ingredients are or the reasons include, neither of which stands alone.
Verify: test the illegal version: the team faced: funding, weather and permissions.
Why: The team faced does not stand alone, so that colon would be wrong — which confirms the rule is about the left side.
Answer: yes, the colon is legal
Step zero
Before reading the sentence for meaning.
Discussion prompt
You reach a question where the four choices differ only in punctuation. What is your first action?
Hint: It involves covering part of the sentence.
Answer:
Cover everything after the punctuation point and ask whether what remains is a complete sentence.
Then cover everything before it and ask the same about the other side.
Those two answers determine which marks are legal, and you can then filter the choices mechanically.
What you do NOT do is read it aloud. Punctuation is inaudible — a comma splice and a correctly joined sentence sound identical, because the pause is the same.
And you do not read for meaning first. Meaning matters only when two choices are both structurally legal, which is the minority of cases.
Worked example
"The equipment we ordered ___ three microscopes and a centrifuge ___ arrived on Tuesday." Which marks?
Figure (svg): An interrupting element fenced by two dashes
Identify the interrupting material: three microscopes and a centrifuge.
Why: It sits between the subject and its verb, describing the equipment.
Delete it and check: the equipment we ordered arrived on Tuesday. Complete and sensible.
Why: So the material is non-essential and needs fencing.
Fence it with a matched pair: two dashes, or two commas.
Why: Both marks must be the same kind; mixing them is never legal.
Two commas would also be correct here. Dashes are used when the interruption already contains commas, as this one does.
Verify: test the mixed version: a dash opening and a comma closing.
Why: That leaves a single comma between the subject and its verb, which is illegal — confirming the pair must match.
Answer: two dashes, or equally two commas
Worked example
"Students who arrive late will be marked absent." Should there be commas around who arrive late?
Figure (svg): An identifying clause shown without fencing marks
Delete the clause and read what remains: students will be marked absent.
Why: The deletion test decides whether material is essential.
That changes the meaning — it now says ALL students will be marked absent.
Why: The clause was identifying WHICH students, so it is essential.
Essential material takes no punctuation at all.
Why: Commas would signal that the clause could be removed without loss.
The deletion test settles both directions: if removing it changes the meaning, no commas; if removing it leaves the meaning intact, use a matched pair.
Verify: compare with a non-essential case: my brother, who lives in Osaka, sent a parcel.
Why: You have one brother, so the clause is extra information and takes commas.
Answer: no commas — the clause is essential
Faded example
From memory. The four lines that decide every question.
Fill in the blanks
Both sides complete: use a period, a semicolon, a colon, or a comma plus a FANBOYS word. First side complete only: a colon may introduce what follows. And the one join that is never legal between two complete sentences is a bare comma.
Why: Note the asymmetry in the third line: a colon cares only about what is to its LEFT, while a comma-plus-FANBOYS join requires complete sentences on both sides. That difference is what makes colon questions feel different from joining questions.
Worked example
"The results were inconclusive ___ however ___ the team published anyway." Which marks?
Figure (svg): The three-part pattern of semicolon, transition and comma
Test both sides: both are complete sentences.
Why: So a legal join is needed between them.
However is not one of the seven FANBOYS words, so a comma before it cannot join the clauses.
Why: A comma plus however is a splice with a word inserted.
The correct pattern is a semicolon before however and a comma after it.
Why: The semicolon does the joining and the comma sets off the transition word.
The missing comma after the transition is the most common near-miss on this type. The semicolon is usually right and the comma is dropped.
Verify: check the alternative: a period would also work — the results were inconclusive. However, the team published anyway.
Why: Both are legal; the semicolon signals a closer relationship between the clauses.
Answer: a semicolon before however and a comma after it
Fill the middle
Non-essential elements and the deletion test.
Fill in the blanks
A non-essential element is fenced by two marks of the same kind. To test whether material is non-essential, delete it and see whether a sensible sentence remains. Essential material takes no punctuation. And a single comma may never stand between a subject and its verb.
Why: The deletion test in the second blank settles both directions at once: if the sentence survives intact, use a matched pair; if the meaning changes, use nothing. It is the only test needed for the whole non-essential half of the type.
Estimation
One choice can usually go without any reading.
Predict first
Both sides of the punctuation are complete sentences. Which choice can you eliminate immediately?
Correct: A bare comma
Why: A bare comma between two complete sentences is a comma splice, which is never legal. The other three are all among the four legal joins. This elimination requires no reading of the sentence for meaning at all — once you know both sides are complete, the splice is disqualified on structure, and it is offered on almost every question of this type.
Check
Cover from the colon onward.
Check your understanding
Which sentence uses punctuation correctly?
Answer: A
Why: Covering everything from the colon onward leaves the survey revealed one clear pattern, which stands alone as a complete sentence. A colon requires exactly that, and what follows may be anything.
The three wrong choices all have a colon introducing something that reads naturally. The rule is entirely about the left side, and all three fail there.
Section
Section 4
Trap
The trap. The choice reads: the museum closed early, the exhibit had been damaged.
It sounds entirely natural, because a comma and a period produce the same pause when read aloud.
But both sides are complete sentences, and a bare comma cannot join them.
The fix. Test both sides for completeness, then check whether the mark offered is among the four legal joins.
A bare comma never is.
Trap
The trap. The choice reads: the data were incomplete, however, the team published.
However looks like it is doing the joining, so the commas feel justified.
However is not a coordinating conjunction. This is a comma splice with a word dropped into it.
The fix. Remember that only the seven FANBOYS words may follow a comma to join two complete sentences.
Transition words such as however, therefore and moreover need a semicolon before and a comma after.
Error analysis
A sentence that reads naturally and breaks a rule.
Annotate
On: \( \text{The museum closed early, the exhibit had been damaged.} \)
This is the clearest case on the test where reading aloud provides no information at all. Punctuation is silent, so the ear has nothing to work with and the procedure must do everything.
Trap
The trap. The choice reads: the ingredients are: flour, eggs and salt.
The list after the colon looks exactly like what a colon should introduce, so the sentence feels right.
But the ingredients are does not stand alone, and a colon requires a complete sentence to its left.
The fix. Cover everything from the colon onward and check what remains.
If it does not stand alone, no colon.
Elimination
"The prototype failed its first trial ___ the design team rebuilt it within a month."
Eliminate the wrong options
Which choice is legal? Both sides are complete sentences.
Survives elimination: a
Why: Both sides stand alone, so the legal joins are a period, a semicolon, a colon, or a comma plus one of the seven FANBOYS words. Only the semicolon appears among the choices. Each wrong answer is a distinct illegal join — the splice, the transition-word splice, and the run-on — and all three were eliminated on structure without reading the sentence for meaning.
Trap
The trap. The choice reads: the equipment we ordered — three microscopes and a centrifuge, arrived on Tuesday.
The interruption is correctly identified and correctly opened with a dash.
It is closed with a comma, and the marks must match. The mismatch also leaves a single comma between the subject and its verb.
The fix. Check that the opening and closing marks are the same kind.
Two commas, two dashes or two parentheses — never one of each.
Counterexample
A method most students use and should not.
Discussion prompt
A student says they choose punctuation by reading the sentence aloud and putting a comma where they pause. Give a counterexample.
Hint: Think about what a comma and a period sound like.
Answer:
Counterexample: the trail was icy, we turned back.
Read aloud, the pause is exactly right — it is the pause you would make at a period too. So the ear approves a comma splice.
A second counterexample in the other direction: the students who arrived late were marked absent. Read aloud, most people pause after late, and a comma there would be illegal — it would separate the subject from its verb.
The mechanism: punctuation is largely inaudible. A comma, a semicolon and a period all produce a pause, and the differences between them are not spoken.
So the ear cannot distinguish them, and the pause test produces splices and subject-verb separations reliably.
The corrected method: test each side for completeness, which is a question about structure that speech does not encode.
Edge cases
The test decides most questions. What about the cases it does not settle?
Discussion prompt
When are two choices both structurally legal, and what decides between them?
Hint: Four legal joins exist, and a question may offer two.
Answer:
When both sides are complete, four joins are legal, and a question sometimes offers two of them.
Then meaning decides. A colon signals that the second clause explains or specifies the first. A comma plus so signals consequence. A semicolon signals close relation without naming it. A period signals separation.
A second unsettled case: when both sides are complete AND the second explains the first, both a colon and a semicolon are defensible. The SAT usually avoids offering both.
A third: commas and dashes are both legal for a non-essential element. Dashes are preferred when the interruption already contains commas, as in a list.
But structure narrows the field first, always. Only after the illegal choices are gone does meaning enter — and by then there are usually only two candidates.
Check
Delete and see what remains.
Check your understanding
Which sentence punctuates correctly?
Answer: A
Why: The clause is non-essential — deleting it leaves the archive reopened in March, which is complete and unchanged in meaning — so it needs a matched pair of commas. Only the first choice has both.
Three of the four fail by leaving one end unfenced or by mixing marks. The deletion test identifies the material and the matching rule then settles the punctuation.
Section
Section 5
Matching
Six situations, six answers.
Match the pairs
Why: Two of the six rows call for NO punctuation, which is worth noticing. Students under time pressure tend to add marks, and on this type the correct answer is quite often the choice with the fewest.
Sorting
Each contains one punctuation decision.
Sort into buckets
Is it correct?
Items (c) and (d) are the same list introduced two ways, and only the left side differs. That pair is worth memorising as the colon rule in miniature.
Comparison
Fill the blanks from memory. All four join two complete sentences.
Comparison matrix
| join | what it signals | watch out for |
|---|---|---|
| Period | full separation | nothing — always available |
| Semicolon | a close relationship | a transition after it needs a comma |
| Comma plus FANBOYS | the relationship the conjunction names | only those seven words qualify |
| Colon | the second explains the first | the left side must be complete |
The watch-out column contains the three most common near-misses on the type: the missing comma after a transition, a non-FANBOYS word after a comma, and a colon after a fragment.
Trade off
Fill in what each method is worth here.
Comparison matrix
| method | what it detects | what it misses |
|---|---|---|
| Reading aloud | roughly nothing | splices, since a comma and a period sound alike |
| Pausing where it feels natural | roughly nothing | it produces subject-verb commas, which are illegal |
| The complete-sentence test | every joining error | nothing, when applied to both sides |
| The deletion test | essential against non-essential material | nothing — it settles both directions |
The top two rows are the methods most students use, and both detect essentially nothing. Punctuation is silent, which is exactly why this type must be answered by procedure.
Real world
One minute on why punctuation rules exist at all.
Discussion prompt
The comma splice is the most-corrected error in English. Why does it matter, given the meaning is usually clear?
Answer:
Punctuation marks the boundaries of ideas, and a reader uses those boundaries to parse a sentence before understanding it.
A splice removes a boundary that the grammar requires, so the reader briefly runs two ideas together and has to reparse.
Most of the time this costs almost nothing — which is why splices are so common and so hard to notice.
Sometimes it costs a great deal. In legal and technical writing, where a clause boundary determines what a condition applies to, the mark carries real meaning.
And the colon rule has a genuine function: it promises the reader that what follows will specify or explain what came before, which is why a colon after a fragment feels unsettling even when the meaning is obvious.
The practical value for a writer: these are the errors that survive proofreading, because the ear approves them. Knowing the tests is the only reliable defence.
Ranking
All four join the same two complete sentences. Order from weakest separation to strongest.
Put in order
Why: A comma plus a conjunction binds the clauses most tightly, since the conjunction names the relationship explicitly. A colon points forward, keeping the two closely connected while marking that the second explains the first. A semicolon separates more, signalling relation without naming it. A period separates completely. All four are legal here, and the ordering is a matter of degree rather than of rule — which is exactly why meaning decides when structure has left more than one option standing.
Concept
This type is 11.2 per cent of the section and is the most rule-governed on the test, which makes it the fastest of all to improve.
| session | what you do | why |
|---|---|---|
| 1 | Classify forty stretches of text as complete or fragment, with no punctuation questions at all. | Everything else is a lookup once this classification is instant. |
| 2 | Twenty joining questions, testing both sides before looking at any choice. | Builds the two-question routine that decides the type. |
| 3 | Fifteen colon and dash questions, covering everything from the mark onward. | The left-side rule is easy and is applied to the wrong side under pressure. |
| 4 | Fifteen non-essential questions using the deletion test, including essential cases. | The deletion test settles both directions and is under-practised. |
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Explain it to yourself
Close the deck.
Discussion prompt
Without looking, state the test, the four legal joins when both sides are complete, and what a colon requires.
Hint: One question asked twice, then a lookup.
Answer:
The test: is what comes before the punctuation a complete sentence, and is what comes after it one too?
Both complete: a period, a semicolon, a colon, or a comma plus one of the seven FANBOYS words — for, and, nor, but, or, yet, so.
A colon requires a complete sentence to its LEFT and nothing in particular to its right.
A bare comma between two complete sentences is a splice, and it is never legal.
If you added that a transition word such as however needs a semicolon before and a comma after, you have the near-miss that catches most people.
Explain it
Two minutes, out loud.
Discussion prompt
How would you explain, without using the word clause, why a comma cannot join two sentences?
Answer:
Say what a comma is: a pause inside a sentence. It separates parts of one thought.
A comma is not strong enough to end a sentence, so it cannot sit between two things that are each already a whole sentence.
Demonstrate it. Write: the trail was icy, we turned back. Cover the second half and ask whether the first is a whole sentence — yes. Cover the first and ask the same — yes.
So there are two whole sentences here, and the only thing between them is a pause mark.
Then give the four repairs: a full stop, a semicolon, a joining word after the comma, or a colon. Any of the four makes the boundary strong enough.
And the warning: it sounds fine either way, because a comma and a full stop are the same pause when spoken. That is why the test has to be done on paper rather than by ear.
Commit first
Commit before you check.
Predict first
Which sentence uses the colon correctly?
Correct: The committee reached one conclusion: the project should proceed
Why: Cover everything from the colon onward. Only the first choice leaves a complete sentence standing — the committee reached one conclusion. The second leaves the committee concluded, which needs an object. The third leaves what the committee decided was, which is incomplete. The fourth leaves a prepositional phrase with no verb. A colon cares only about its left side, and three of the four fail there.
Connect it up
Blank paper.
Draw it
Draw a flowchart. At the top ask: is what comes BEFORE the punctuation a complete sentence? Branch yes and no. Down the yes branch, ask the same about what comes AFTER. If both are complete, list the four legal joins: period, semicolon, colon, and comma plus FANBOYS — writing out for, and, nor, but, or, yet, so. If only the first is complete, write that a colon or dash may introduce what follows. If neither is complete, write that you probably need no punctuation at all. To one side, draw a sentence with an interruption fenced by two matching marks, with the deletion test beside it. At the bottom, in large letters: A BARE COMMA CAN NEVER JOIN TWO SENTENCES.
Exit ticket
One question before you close the deck.
Predict first
The four choices differ only in punctuation and you are unsure. What do you do?
Correct: Test whether each side of the punctuation is a complete sentence
Why: The completeness test settles every question of this type mechanically, and it is the only method that works. Reading aloud detects nothing, because a comma and a period produce identical pauses. More punctuation is not better — essential material takes none at all. And defaulting to the comma selects the comma splice, which is the single most frequently offered wrong answer in the type.
Recap
One type, one question asked twice: is each side a complete sentence?
| never do this | do this instead |
|---|---|
| Choose punctuation by reading aloud | Test whether each side is a complete sentence |
| Join two sentences with a bare comma | Use one of the four legal joins |
| Write a comma before however | Use a semicolon before it and a comma after |
| Put a colon after the ingredients are | The left side must stand alone |
| Open with a dash and close with a comma | Match the two fencing marks |
| Put a comma after a long subject | A pause is not a rule |
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