Parallel Structure: the rule, with examples
Parallel structure means items joined in a sentence share the same grammatical form — all nouns, all -ing verbs, or all clauses. “She likes hiking, swimming, and biking” is parallel; “hiking, swimming, and to bike” is not. Paste your own sentence into the free checker below to fix it in one click.
Parallel structure means items joined in a sentence share the same grammatical form — all nouns, all -ing verbs, or all clauses. “She likes hiking, swimming, and biking” is parallel; “hiking, swimming, and to bike” is not.
How it works
- 1Spot the pattern. Look at anything joined by “and”, “or”, or a pair like “not only… but also”. Read the items as a vertical list — if one doesn’t match the shape of the others, the structure has broken.
- 2Apply the rule. Rewrite the odd item to match the form of the rest. Usually the cleanest fix is to make every item a gerund (“-ing”) or every item a plain noun or adjective.
- 3Check your sentence. Paste your text into the grammar checker below — it flags the issue and shows the correction.
- 4Re-read it. Read the corrected version aloud to confirm it says exactly what you meant.
The rule
When you list or compare two or more items in a sentence, every item must take the same grammatical form. If the first item is a gerund (-ing), they all are; if the first is an adjective, they all are.
How to spot it
Look at anything joined by “and”, “or”, or a pair like “not only… but also”. Read the items as a vertical list — if one doesn’t match the shape of the others, the structure has broken.
How to fix it
Rewrite the odd item to match the form of the rest. Usually the cleanest fix is to make every item a gerund (“-ing”) or every item a plain noun or adjective.
The most common mistake
Mixing a gerund with an infinitive (“reading, writing, and to jog”) or tacking a full clause onto a list of adjectives (“bold, innovative, and it cost a lot”). If you’re not sure whether your sentence has the problem, paste it into the checker above — it catches this and explains the fix in plain language.
| ❌ Incorrect | ✓ Corrected | Why |
|---|---|---|
| I like to read, writing, and to jog. | I like reading, writing, and jogging. | All three items are gerunds |
| The plan was bold, innovative, and it cost a lot. | The plan was bold, innovative, and expensive. | All three are adjectives |
| She is responsible for hiring, training, and to evaluate staff. | She is responsible for hiring, training, and evaluating staff. | Parallel gerunds after “for” |
Frequently asked questions
Which sentence uses parallel structure?
The one where every listed or compared item shares the same grammatical form. “We came, we saw, we conquered” is parallel (three matching clauses); “We came, seeing the city, and conquered” is not.
Why does parallel structure matter?
It makes sentences easier to read and signals careful writing. Faulty parallelism is one of the most common marks graders and editors flag, even when a sentence is otherwise correct.
How do I check my own writing for this?
Paste your text into the free grammar checker on this page. It flags the issue, suggests a correction, and explains why — so you learn the rule, not just the fix.
Is it free?
Yes — 3 free runs every day with up to 500 words per run, no credit card to start. Upgrade for a larger word pool, or use the free iOS app.