Walnuts have hard shells is that a singular or plural pronouns how would I rewrite it in a sentence

It is a plural pronoun

Scentence: Walnuts have hard shells. (I think but the frist answer is correct)

Explanation: Scentence: Walnuts have hard shells. (I think but the frist answer is correct)

the sentence does not violate the phrase structure second rule (introduced by noam chomsky) because noun phrases consist of a determiner such as a, the or every, and a noun. in the sentence, the noun phrase the cake includes a determiner (the) and a noun (cake).

on the other hand, the first rule indicates that a sentence encloses a noun phrase, followed by a verb phrase. the example sentence can be analysed as follows:

john (n) + ate (v) + the (det) + cake (n).