Conjoined items in a sentence must be in the same grammatical form.
| Incorrect: | I like to jog and walking . |
In the above sentence, to jog and walking are not parallel in grammatical construction.
Parallelism is the matching of the forms of words, phrases, or clauses within a sentence. Editing your work for parallel construction improves clarity and emphasizes your points.
Conjoined items in a sentence must be in the same grammatical form, i.e. grammatically parallel.
To avoid faulty parallelism, the sentence above should be corrected to:
| Correct: | I like jogging and walking . |
Words, phrases, and clauses joined by a coordinating conjunction (and, but, or, nor, for, so, yet) need to have parallel grammatical construction.
| Incorrect: | We all need good nutrition and to exercise on a regular basis. |
| Correct: | We all need good nutrition and regular exercise . |
Words, phrases, and clauses joined by a correlative conjunction (not only. but also, both. and, either. or, neither. nor) need to have parallel grammatical construction.
| Incorrect: | like both to read books and watching movies. |
| Correct: | like both to read books and to watch movies. |
Words, phrases, and clauses joined by a comparative expression (as much as, more than, less than) need to have parallel grammatical construction.
| Incorrect: | enjoy going out to a movie as much as I like to rent a movie and stay home to watch it. |
| Correct: | enjoy going out to a movie as much as I enjoy renting a movie and staying home to watch it. |
Items joined by a coordinating or a correlative conjunction, or by a comparative expression need to be parallel in their grammatical form.
In the following example, inserting because before each of the elements makes each point a subordinate adverbial clause and adds to the clarity of the whole sentence.
| Incorrect: | Many people maintain a healthy diet because they want to look healthy, it increases their energy, and they want to live longer. |
| Correct: | Many people maintain a healthy diet because they want to look healthy, because it increases their energy, and because they want to live longer. |
Words, phrases, and clauses in a series should be parallel in grammatical construction.
| Incorrect: | He is smart , honest , and has a great sense of responsibility. |
| Correct: | He is smart , honest , and very responsible . |
Items in a bulleted list should also be parallel in their grammatical form. For example,