Parallel Structure
When a sentence lists or compares ideas, those ideas have to be dressed in the same grammatical 'uniform.' Mismatched forms are an easy trap the test loves — and an easy point once you can spot them.
| Structure | Broken | Parallel |
|---|---|---|
| List | hiking, swimming, to bike | hiking, swimming, biking |
| Pair (and/or) | patience and to be organized | patience and organization |
| Comparison | scores were higher than the group | scores were higher than those of the group |
The same idea, fixed so the joined parts match in form.
How to spot it on the test: When you see a list, a pair joined by and/or, or a comparison word (than, as, compared with), check that the connected pieces match in form. Pick the answer choice that makes them match. You don't need to name the part of speech — you just need them to be consistent with each other.
A quick rule chain for parallelism questions.
Parallelism questions reward pattern-matching. Find the items being joined, look at the form of the ones that are already correct, and choose the answer that follows the same pattern.
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
Choose the option that completes the sentence following the conventions of Standard English:
The internship taught Maria how to analyze data, write clear reports, and _______ to a professional audience.
Choose the option that completes the sentence following the conventions of Standard English:
The researchers found that the migration patterns of the coastal birds were more predictable than _______ inland birds.
Common pitfalls
In comparisons, students compare a thing to the owner of the thing (scores to a group, patterns to birds). Always ask: what noun is on the left side? The right side must be that same noun — often signaled by that (singular) or those (plural).
An answer choice can mean the right thing but be the wrong grammatical form. 'Hiking, swimming, and to bike' all describe activities, but the forms don't match. Check the form (verb? noun? -ing?), not just the idea.
Phrases like 'the presentation of findings' sound sophisticated but break the pattern. Parallelism usually favors the simplest choice that matches the other items, not the wordiest one.
Use that for a singular noun and those for a plural noun. Matching the wrong number is a classic trap (e.g., 'that of the inland birds' when the noun is the plural patterns).
Key takeaways
Items in a list, pairs joined by and/or/but, and comparisons must share the same grammatical form.
To fix a list, copy the form of the items that are already correct.
In comparisons, use 'that' (singular) or 'those' (plural) to stand in for the repeated noun so both sides match.
Match the form, not just the meaning — and don't reflexively pick the longest choice.
Try it yourself
5 practice questions on Parallel Structure, drawn from the question bank. The tutor is one click away if you get stuck.