What are auxiliary verbs, modal verbs, connective verbs and examples in English

What are auxiliary verbs, modal verbs, connective verbs and examples in English

The copula is a connective verb, which forms a copula structure with the predicative. It has no special usage. For example, am in I am a student is a copula, and the verbs that express the senses can be used as copulars. Auxiliary verbs refer to the auxiliary verbs, such as do have / has, when a verb cannot be completed independently when it wants to express a tense