Form, Structure, and Sense
About a quarter of the Writing questions test whether a sentence's grammar holds together — subject-verb agreement, verb tense, and pronouns that match what they refer to. Master these rules and you can earn points fast without reading a long passage.
The verb agrees with 'box' (singular), not the nearby 'nails.'
2. Verb tense. Tense tells you when something happened. The tricky one tested here is the past perfect (had + verb), which marks an action that happened before another past action. In She had finished dinner before the guests arrived, the finishing came first, so it gets had finished.
| Happened first | Happened second | Example |
|---|---|---|
| Past perfect (had + verb) | Simple past | She had finished before they arrived. |
| had published | turning forty | She had published three books before turning forty. |
The earlier of two past events takes the past perfect.
Check your understanding with a question from this topic:
The novelist, who _______ three bestsellers before turning forty, credits her prolific output to a disciplined daily writing routine.
Which choice completes the text so that it conforms to the conventions of Standard English?
Worked examples
Each of the experiments _______ a different variable, allowing the team to isolate which factor mattered most.
Which choice completes the text so that it conforms to the conventions of Standard English?
By the time the rescue crew reached the summit, the storm _______ for several hours, leaving the trail nearly impassable.
Which choice completes the text so that it conforms to the conventions of Standard English?
Critics praised the director's later films for their bold visuals, but many viewers still prefer the quiet intimacy of _______ earlier work.
Which choice completes the text so that it conforms to the conventions of Standard English?
Common pitfalls
In The box of nails (is/are) heavy, students grab nails and pick are. Always find the true subject (box) and ignore the prepositional phrase between it and the verb.
Phrases like before, by the time, after, and had already signal that one action came before another. If you skip them, you'll miss when the past perfect had + verb is required.
their/they're/there, its/it's, and whose/who's sound identical but mean different things. Test each by expanding the contraction: if they are doesn't fit, it isn't they're.
The scores were higher than the other group compares scores to people. Use than those of the other group so you compare scores with scores. Watch for missing those/that.
Key takeaways
Find the real subject and make the verb agree in number — cross out phrases in between.
Time clues like 'by the time' or 'before' often call for the past perfect ('had' + verb).
A pronoun must match its antecedent in number; 'those/that' must point to a clear, parallel noun.
'Data' is plural in formal writing ('the data are'); 'each/every/one of' are singular.
These questions have exactly one correct answer — plug in each choice and find the grammar break.
Watch & learn
Curated Khan Academy walkthroughs on Form, Structure, and Sense. They're complementary to this lesson — watch one if a written explanation isn't clicking, or after to reinforce.
Try it yourself
5 practice questions on Form, Structure, and Sense, drawn from the question bank. The tutor is one click away if you get stuck.