Study the sentences below:
To achieve clarity and meaning in your speaking and writing, you should always remember that grammatical elements joined by conjunctions should have the same grammatical form and perform the same grammatical function.
For instance, in sentence 1, the italicized groups of words have parallel elements using the –ing form. In sentence 2, the italicized groups of words are also parallel in structure, consisting of words that combine the preposition to and the base form of the verb. In sentence 3, the parallel structure consists of a preposition and a noun.
On the other hand, sentences 4 and 5 make use of conjunctions but and so to combine two independent clauses together.
What do you call the groups of words with parallel structure found in sentences 1, 2, and 3? These groups of words are called phrases.
As you already know, a phrase is a group of words that does not have a subject and a predicate. Hence, it does not convey a complete idea and cannot stand alone. For it to make sense, it should be made part of a sentence. In the examples given, the structures of all the phrases are parallel or similar, which means that all the phrases are of equal weight or importance.