Parallelism

Parallelism is the grammatical balance of a sentence. It allows for the sentence to flow and have rhythm when read. A sentence that lacks parallelism causes confusion in the focus of the sentence and the rhythm.

Example: Great Parallelism

                                    The New York Times February 22

Explanation:

The use of the infinitive "to be" in the sentence is paired with complement nouns "sponsor" and supplier. Both words start with s and happen to end in an "--er" sound adding to the balance of the sentence. If supplier was changed to " to supply"  it would not be balanced, supplier would be changed to a verb where sponsor is a noun.