In short
About 26 percent of SAT Reading and Writing, roughly 11 to 15 scored questions, tests grammar and punctuation. The most tested rules are joining two complete sentences correctly (period, semicolon, or comma plus conjunction), colon use, setting off extra information, subject verb agreement, pronoun agreement and modifier placement.
About a quarter of the SAT Reading and Writing section tests grammar and punctuation. College Board calls this domain Standard English Conventions, and it is the most learnable part of the section: the same small set of rules comes up again and again. Learn the rules below and these questions become some of the fastest points on the test.
What the grammar questions look like
Each question shows a short passage with one blank and four options. The options differ only in punctuation or in the form of a word, and you choose the one that makes the sentence correct. There are two skill areas:
| Skill | What changes between the options | Typical topics |
|---|---|---|
| Boundaries | Punctuation | Periods, semicolons, colons, commas, dashes |
| Form, Structure, and Sense | Words and word forms | Agreement, verb tense, pronouns, possessives, modifiers |
Standard English Conventions makes up about 26 percent of the section, roughly 11 to 15 scored questions out of 50.
Boundaries: the punctuation rules
Rule 1. Two complete sentences need a strong boundary
An independent clause has a subject and a verb and can stand alone. Two of them can be joined by:
- a period: The museum opened in 1902. It still draws large crowds.
- a semicolon: The museum opened in 1902; it still draws large crowds.
- a comma plus a conjunction (and, but, or, so, yet, for, nor): The museum opened in 1902, and it still draws large crowds.
A comma alone is wrong. The museum opened in 1902, it still draws large crowds is a comma splice, and it is the single most tested error.
Rule 2. Words like "however" do not join sentences
However, therefore, moreover and similar words are not conjunctions. Between two complete sentences they need a semicolon or a period before them: The trial was small; however, the results were clear.
Rule 3. A colon follows a complete sentence
Use a colon to introduce a list, an explanation or an example, but only after a clause that could stand on its own: The recipe needs three things: flour, water and salt. Never put a colon right after a verb or a preposition: The recipe needs: flour is wrong.
Rule 4. Extra information takes matching punctuation on both sides
A nonessential phrase can be removed without breaking the sentence. Set it off with two commas, two dashes or two parentheses, and never mix them: The author, a former engineer, wrote the novel in a year.
Rule 5. No punctuation between essential parts
Do not separate a subject from its verb, a verb from its object, or a title from the name that follows when the name is essential: The biologist Rachel Carson wrote Silent Spring needs no commas.
Form, Structure, and Sense: the word rules
Rule 6. Subjects and verbs agree
Find the real subject, ignoring phrases in between: The list of required documents is short. The subject is "list", not "documents".
Rule 7. Pronouns agree with what they refer to
Each of the cities announced its plan. "Each" is singular, so the pronoun is "its", not "their". Collective nouns such as company, team and committee also take "it" on the SAT.
Rule 8. Verb tense follows the timeline
Look at the other verbs and time words in the passage. If the passage describes a finished event in the past, the blank is in the past tense too.
Rule 9. Possessives and plurals
- one researcher's notes (singular possessive)
- two researchers' notes (plural possessive)
- its means belonging to it; it's means it is
Rule 10. A modifier names the thing right next to it
Walking along the river, the bridge came into view says the bridge was walking. Correct: Walking along the river, we saw the bridge. When a sentence starts with a descriptive phrase, the subject right after the comma must be the one doing it.
A five step routine for every grammar question
- Look at what changes between the options: punctuation or words.
- Find the subject and the verb of each clause around the blank.
- Decide whether you are joining two complete sentences or not.
- Eliminate every option that breaks a rule above.
- Choose the shortest correct option if two seem acceptable.
How to practice
Grammar improves quickly with focused sets. Do 15 to 20 questions on one rule at a time, read the explanation for every mistake, then mix the rules together. The rest of the section tests reading and reasoning skills; see our guide to SAT Reading and Writing question types. For vocabulary in context questions, our SAT vocabulary lists cover the words that appear most often.
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Frequently asked questions
How many grammar questions are on the SAT?
Standard English Conventions makes up about 26 percent of Reading and Writing, roughly 11 to 15 of the 50 scored questions.
What is the most common SAT grammar mistake?
The comma splice: joining two complete sentences with only a comma. Use a period, a semicolon, or a comma with a conjunction such as and or but.
Can I use a semicolon before however on the SAT?
Yes. When however connects two complete sentences, it needs a semicolon or a period before it and a comma after it.