Why this matters on the SAT
A colon makes a promise: a full sentence comes first, and what follows explains or lists what it said. The SAT tests that promise right after words that could end a statement, where the choices offer a colon or sometimes a single dash, and it tests lists by putting the blank between their items. Together, these questions make up about one in ten grammar questions, and they're really asking two things: do the words before the blank stand alone, and does what follows list or explain what they said?
Solution to the example
The blank comes where a statement could end, so test the colon. Cover the blank and what follows: They face a persistent problem stands alone. Then read on: a colony's shape can change dramatically after storms has its own subject and main verb, shape can change, so a second full sentence follows, and it says what the problem is. A colon joins a full sentence to one that explains it. The answer is B. C tempts most, because a comma sits where you'd pause, but a comma alone between two full sentences is a comma splice. No mark (A) or “and” with no comma before it (D) runs them together.
SAT example
Marine ecologists who monitor coral colonies over many years cannot rely solely on a colony's outline to identify it. They face a persistent _____ a colony's shape can change dramatically after storms, making comparisons between older and newer photographs difficult.
Which choice completes the text so that it conforms to the conventions of Standard English?
problem
problem:
problem,
problem and
A colon can follow only a full sentence. To test one, cover the colon and everything after it: the words left must stand alone. In the examples, the mark being tested is bold, with a word on each side, and the words a test covers are struck through.
The bakery sells three kinds of bread has a subject and a main verb, so it stands alone, and the colon works. The bakery sells doesn't: sells what? That's the test from lesson 5 run in reverse. No colon goes between a verb or a preposition and its object, or after including or such as, because the words before it stop short.
After the colon comes what the full sentence promised: a list, a phrase, or a whole second sentence that explains it.
What follows decides which marks compete with the colon, and the next sections take each case in turn, the second sentence first, since the SAT tests it most. But the first test is always the words before the colon, and it's a test on all of them, not on the last word: a sentence can end on a preposition when its object came earlier.
About what? One rule, earlier in the sentence. So The bakers have one rule they never argue about stands alone, and a colon can follow it.
When the words after the colon can stand alone too, two full sentences meet there. Between two full sentences, a colon says the second explains the first. Lesson 2's rules still hold: a comma alone makes a comma splice, and no mark, or “and” with no comma before it, runs them together.
Split at the blank, as in lesson 2: The bakery has one rule stands alone, and so does every loaf is baked that morning, which says what the rule is. The comma splice tempts most, because the comma sits where you'd pause.
A period or a semicolon would also join two full sentences, so when a colon is right here, the SAT doesn't offer a plain period or semicolon beside it. The wrong choices are usually lesson 2's errors. Most of these sentences set up the colon with a word that announces something, like problem, rule or conclusion, but some don't, so test the words before the blank, not the announcing word.
When a plain period or semicolon does sit beside the colon, check the meaning: a second sentence that turns against the first, or only adds to it, doesn't explain it, so the period or the semicolon is the answer.
On this SAT question, check that the words before the blank stand alone, then read what follows for a subject and a main verb of its own.
Practice problem
Rather than banning drones outright, the park service adopted a rule aimed at reducing disturbance to _____ pilots must keep their devices at least 500 feet from nesting sites.
Which choice completes the text so that it conforms to the conventions of Standard English?
More than a third of these questions start the second sentence with a part that can't stand alone, such as a whereas or when part, or a phrase, so the words after the blank look like a fragment. Read past the comma that closes the opening part: if a subject and a main verb follow, the words after the blank are a full sentence, as When the new bridge opened, the ferry stopped running is in lesson 2. In these examples, the subject and main verb that follow the opening part are underlined.
When a loaf comes out cracked leans, but the bakers keep it for themselves follows, with its own subject and main verb. So a full sentence starts at the blank, and a comma alone before it makes a splice.
The second sentence can also open with an -ing phrase that turns out to be its subject. Read on for the main verb and ask what, as lesson 2 showed:
What is never allowed? Keeping a loaf past noon. The whole -ing phrase is the subject of is, so the words after the colon are a full sentence.
Comma or colon at the blank? The ferry crew follows one rule ______ when fog rolls in, the ferry stays at the dock.
Now the other case: what follows the colon can't stand alone. When a list or a phrase explains a full sentence, a period or a semicolon before it leaves a fragment, so a colon attaches it.
Rye, spelt, and sourdough has no verb at all, so it can't stand alone. Outside a list, the period and the semicolon do the same job, as lesson 2 showed, so when both appear in the choices, they cancel out.
The comma fails another way: before a list, it reads as one more comma of the list, so bread looks like the first of four items. Before a list, the colon wins.
A phrase can look like a sentence. A noun followed by an -ing word, like the ovens glowing all night, has no main verb, since an -ing word needs a helper to be one: glowing → were glowing. So it's a phrase, and a semicolon before it leaves a fragment. With no mark, the phrase runs into the sentence.
Before a phrase, check what the phrase does. A colon fits only when what follows says what something before it is, lists it, or explains it: what sight? The ovens glowing all night. A part that only adds what someone did, or when, isn't that, so the colon is wrong. A phrase that adds what someone did takes lesson 3's one comma, and a part that says when usually takes no mark, as lesson 5 showed.
Colon or comma at the blank? The ferry left the dock at dawn ______ carrying forty passengers to the island.
On this SAT question, test the words before the blank, then ask whether what follows could stand alone.
Practice problem
An archive received an unsigned nineteenth-century letter that might have been written by a famous abolitionist. To test the claim, investigators considered three kinds of _____ slant, the ink’s chemical makeup, and the paper’s watermark.
Which choice completes the text so that it conforms to the conventions of Standard English?
After a full sentence, a single dash can introduce a list or a phrase, the way a colon does. It's the dash from lesson 3 that opens extra information at the end of a sentence, and you test it the same way: the words before it must stand alone.
So when a colon and a single dash sit at the same spot in the choices, they do the same job, and neither is the answer, unless a dash at the blank would pair with a single dash elsewhere in the sentence (lesson 3). Then lesson 3's pair rule decides. Parentheses can't stand in for the dash: they always come as a pair, so an opening parenthesis needs a closing one before the sentence ends.
A semicolon or a dash at the blank? The ferry’s last stop is a small island ______ a strip of sand with one lighthouse.
A list's items are usually separated by commas. But when any item holds a comma of its own, semicolons separate the items, and the commas inside the items stay.
Each item is a bread and a which part, set off by a comma. With commas between the items too, you couldn't tell where one item ends and the next begins. So the semicolons mark the edges of the items, and each comma stays with its bread.
You don't have to judge this yourself: the sentence already shows the separator. In SAT questions of this kind, a semicolon already sits between two other items, nearly always as “; and” before the last one. Look ahead for it, and copy it at the end of each item. Inside a list, a semicolon has a different job from a period, so the two don't cancel out there: a period would end the sentence and leave the rest of the list a fragment.
Items can hold commas in other ways too: a place and its state (Bath, Maine), a date, or a title and the phrase that renames it. Some choices change two marks, one at the end of an item and one inside the next. Settle the end of the item with the list's separator first, then copy the inside mark from the other items. A list like this often follows a colon, which still needs a full sentence before it.
A comma or a semicolon at the blank? The museum’s ship models come from three ports: Bath, Maine ______ Salem, Massachusetts; and Newport, Rhode Island.
On this SAT question, look ahead for the separator the list already uses, and copy it at the end of the item.
Practice problem
A new exhibition at the maritime museum examines three tools that transformed ocean navigation: the astrolabe, which sailors used to estimate latitude by observing celestial _____ marine chronometer, which enabled navigators to calculate longitude accurately; and the sextant, which allowed users to measure angles between the horizon and celestial objects.
Which choice completes the text so that it conforms to the conventions of Standard English?
When no item holds a comma, commas separate the items. SAT lists also put one before the final “and”, and the sentence usually shows it already.
The bakery sells rye could stand alone, so the colon passes the full-sentence test. But between two items of a list, only the list's own separator can go. A colon or a dash there would make spelt, and sourdough explain rye, when they're more items of the same list. And nothing goes between such as and its first item, as lesson 5 showed.
On this SAT question, find the separator the list already shows, and check whether any item holds a comma of its own.
Practice problem
In many towns, community choirs rehearse in spaces such as ______ halls, and school auditoriums.
Which choice completes the text so that it conforms to the conventions of Standard English?
Here's the move that makes these questions fast. Marks that do the same job cancel out: outside a list, a period and a semicolon, as lesson 2 showed, and after a full sentence, a colon and a single dash, unless a dash at the blank would pair with a single dash elsewhere in the sentence (lesson 3). When two marks that do the same job sit at the same spot in the choices, neither is the answer.
That makes one routine for every question in this lesson, the one the worked examples and the mixed practice problems follow:
In this question, the words after the blank start with an -ing word, so they're built to look like a phrase that a comma could attach.
In this question, each choice changes two marks: one where the full sentence ends and a list begins, and one inside the list's first item.
Worked example
Using residue analysis, archaeologist Samira Bell has identified three culinary preparations once made in vessels excavated at a Bronze Age harbor ______ a fermented barley drink flavored with thyme; in a shallow bowl, lentils cooked with coriander; and in a handled pot, goat milk mixed with wild honey.
Which choice completes the text so that it conforms to the conventions of Standard English?
site, in a narrow-spouted jug:
site; in a narrow-spouted jug,
site: in a narrow-spouted jug,
site in a narrow-spouted jug,
Step 1
Each choice changes a mark after site, where a statement could end, and a mark after jug, inside the list. Start with the first. Cover what follows site: Using residue analysis, archaeologist Samira Bell has identified three culinary preparations once made in vessels excavated at a Bronze Age harbor site stands alone, and what follows lists the three, so a colon fits.
B tempts most, because the list is full of semicolons. But those semicolons separate items, and this mark would come before the first item, where no item has ended yet. So it has to work where a period would, and what follows can't stand alone. In a narrow-spouted jug, a fermented barley drink flavored with thyme and the rest of the list have no main verb: flavored, cooked and mixed only describe (was flavored with thyme). B leaves a fragment.
D has no mark, so the list runs into the sentence, as if the site were in the jug.
Step 2
A and C are left, and they differ in where the colon goes. Look at the list's other items: in a shallow bowl, lentils cooked with coriander and in a handled pot, goat milk mixed with wild honey. Each names a vessel, then a comma, then the dish made in it. So the first item takes the same shape, with a comma after jug.
A puts a comma after site and the colon after jug. That pulls in a narrow-spouted jug into the sentence before the list, where it says all three preparations were made in that jug, though the list puts two of them in a bowl and a pot, and it leaves the first item with no vessel. A is out.
Step 3
C puts the colon where the full sentence ends and a comma inside the first item, so all three items match. The answer is C.
These five questions mix the cases, so on each one, start by finding the job the blank does, then run the routine.
Practice problem
In cathedral design, builders often include decorative elements called _____ spaces that fill the corners between an arch and its rectangular frame.
Which choice completes the text so that it conforms to the conventions of Standard English?
Practice problem
To determine whether urban noise affects birds' dawn songs, ecologist Mara Velez compared recordings from parks at varying distances from major roads. Her analysis revealed a consistent timing ______ dawn chorus beginning earliest in parks beside highways and progressively later as road noise decreased.
Which choice completes the text so that it conforms to the conventions of Standard English?
Practice problem
While cataloging pigments in a set of fifteenth-century manuscripts, researchers used X-ray fluorescence to avoid removing any _____ noting, as conservation scientist Lena Marquez has cautioned, that the technique can miss dyes made from plants, which do not contain the metals the scanner detects.
Which choice completes the text so that it conforms to the conventions of Standard English?
Practice problem
French philosopher and novelist Simone de Beauvoir wrote works as varied as She Came to Stay, a novel depicting the frictions of an open relationship in 1930s ______ a novel based on real people that follows writers reckoning with liberation-era politics; and Memoirs of a Dutiful Daughter, the first volume of her autobiography.
Which choice completes the text so that it conforms to the conventions of Standard English?
Practice problem
In a unit on viscoelastic materials, a lab manual notes that silicone putty can both resist and flow depending on how quickly it is stretched; the manual calls this time-dependent _____ when pulled sharply, the putty snaps, but when pulled slowly, it elongates.
Which choice completes the text so that it conforms to the conventions of Standard English?
Finish the lesson
Finish the remaining questions correctly to complete this lesson.
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