The question "how does he say it " is answered through interpretation analysis evaluation

sing because that is what they are doing in the sentence

explanation:

the simple predicate is the main verb in the predicate that tells what the subject does. example: my father fixed the dryer. read each sentence. draw a line under the complete predicate.

the answer is:

when will (v) the books (n) be (v) due?

nouns refer to people (other than pronouns), places and things, whereas verbs describe actions and are usually part of the predicate of a sentence. finally, pronouns can work as nouns and identify the participants in speech.

in the example sentence, "will" is a verb part or auxiliary verb, "be" is an infinitive verb and "books" is a plural noun.