1, notional verbs can specifically express actions, behaviors, existence, psychological activities, etc.
For example, the notional verbs expressing actions are: say, see, listen, laugh, eat, drink, walk, run, fly, learn and so on.
2. Auxiliary verbs can be divided into modal auxiliary verbs, basic auxiliary verbs and semi-auxiliary verbs.
There are only three basic auxiliary verbs: be, do and have. They have no semantics in sentences, but only grammatical functions, which are helpful to form progressive aspect, perfect aspect, passive aspect, negative sentence, interrogative sentence and so on.
3. Connecting verbs: also called connecting verbs, are verbs used to assist the subject. You can't be a predicate alone, but you must follow a predicate to form a system table structure, which explains the status, nature and characteristics of the subject.
Verbs in English are:
Sell, buy, fight, watch, jump, sing, say, ride, ask and answer.
Write, knock, walk, run, read, learn, fly, watch, watch, say, say, listen, drink, agree, sleep and so on.