What is parallel construction?
Writers must use consistency of form when constructing sentences. This is especially important when the sentence contains more than one related element. These elements should have the same form, or the sentence will seem unbalanced and confusing. When the form is the same, we call it parallel construction. An error in construction is called faulty parallelism.
Ways to ensure parallel construction
1. A list should contain like elements. If the first item in the list is a noun, all the items in the list should be nouns.
Example
She enjoyed parties, presents, and to have her friends around her.
Parties and presents are plural nouns, but to have her friends around her is an infinitive phrase.
A better sentence would be:
She enjoyed parties, presents, and the company of her friends.
2. If the first item in the list is a verb, all the items should be verbs, and the verbs should all be in the same form.
Example
He was running, lifting weights, and tried everything he could imagine to get into shape.
Running and lifting are in the progressive form, while tried is in the past tense.
A better sentence would be:
He was running, lifting weights, and trying everything he could imagine to get into shape.
3. Elements joined by correlative conjunctions should be in the same form.
Example
Neither her repeated efforts nor wanting it desperately helped Gretchen achieve her goals.
Efforts is a noun; wanting is a participle. The forms should match.
A better sentence would be:
Neither her repeated efforts nor her desperate desire helped Gretchen achieve her goal.
4. When listing prepositional phrases that start with the same preposition, either use the preposition before the first object and then leave it out for the rest of the objects, or use it before each object.
Example
The opposition came from the establishment, the government, and from women who wanted to maintain the status quo.
It is not necessary to repeat the preposition from before women.
You can also rewrite the sentence putting prepositions before each of the objects:
The opposition came from the establishment, from the government, and from women who wanted to maintain the status quo.