Parallel Structure
Parallel structure means using the same grammatical form for elements of equal importance in a list or comparison. It makes writing cleaner and easier to read.
What is parallel structure?
Parallel structure (also called parallelism) means that when two or more elements are joined in a list or comparison, they must all be in the same grammatical form.
| Not parallel ✗ | Parallel ✓ |
|---|---|
| She likes swimming, to run, and cycling. | She likes swimming, running, and cycling. |
| He is kind, patient, and a good listener. | He is kind, patient, and attentive. |
| We need to plan, prepare, and the execution. | We need to plan, prepare, and execute. |
Parallel structure with conjunctions
Elements joined by and, but, or, nor, yet must be parallel.
She can speak French and write Spanish. ✓ (verb + verb)
He is tall, dark, and handsome. ✓ (adjective + adjective + adjective)
You can pay by cash or by card. ✓ (prepositional phrase + prepositional phrase)
Parallel with correlative conjunctions
Correlative conjunctions (both…and, either…or, neither…nor, not only…but also) require strict parallelism.
She is both talented and hardworking. ✓ (adjective + adjective)
Not only did he arrive late, but he also forgot the files. ✓ (clause + clause)
Either you call her or you write a letter. ✓ (clause + clause)
Parallel structure in lists
The job requires: strong communication skills, the ability to work in a team, and experience in project management. ✓ (noun phrase × 3)
Faulty parallelism: Not only is she smart, but also works hard ✗ → Not only is she smart, but she also works hard ✓. Make sure both halves have the same structure.
Tip: Read the elements out loud. If one feels out of place — a different word class or form — fix it so all elements match.