Explain the concept of agreement in parallel structure.

In grammar, agreement refers to the correspondence or harmony between different parts of a sentence. When it comes to parallel structure, agreement is crucial in maintaining consistency and balance within a sentence or a series of sentences.

Parallel structure, also known as parallelism, is the repetition of a grammatical structure or pattern within a sentence or between multiple sentences. It involves using the same grammatical form for similar or related ideas, which helps to create a sense of symmetry and clarity in writing.

In the context of agreement in parallel structure, it means ensuring that the elements being compared or contrasted in a sentence are grammatically consistent. This includes maintaining agreement in terms of tense, number, person, and form.

For example, consider the following sentence:

"I enjoy swimming, hiking, and to play tennis."

In this sentence, there is a lack of agreement in parallel structure. The first two elements, "swimming" and "hiking," are in the gerund form, while the third element, "to play tennis," is in the infinitive form. To achieve agreement in parallel structure, the sentence should be revised as:

"I enjoy swimming, hiking, and playing tennis."

Now, all three elements are in the gerund form, maintaining grammatical consistency and agreement.

In summary, agreement in parallel structure ensures that the elements being compared or contrasted in a sentence are grammatically consistent in terms of tense, number, person, and form. It helps to create balance, clarity, and coherence in writing.