Question

helping verbs and main verbs

Answer 1

Helping verbs are those words which are placed before main verbs while main verbs are those words which shows action

Answer 2

(A)Main verb: A verb which has major meaning in terms of action are called main verb, i.e. write, buy, eat etc. 
(B)Helping verb: A verb which supports the main verb to form the structure of sentence (according to a specific tense) and give us information about the time of action expressed by main verb, is called helping verb or auxiliary verb, i.e. is, am, have, was, had, is, will etc.