Parts of Speech - Verb and Auxiliary Verb
  VERB:    Every  human being is doing some actions in the world always. These actions may happen  in the past, present, or future. So we can define a verb as a word of any ACTION  done by any human being. For example, GO, COME, TAKE, BATH, SEE. These words  denote an action of a human being.   Based on the time of action  a verb can be classified as three such as PAST, PRESENT, and  FUTURE.   We will learn more about each of these in  detail.   AUXILIARIES AND AUXILIARY  VERBS:  Auxiliary verb is a word helping a verb. A verb cannot  be separated from verb. Only one auxiliary can help at a time to a  verb.   List of Auxiliary verbs:   Everyone is learning English grammar must memorize these auxiliaries like a song  lines.   IS, AM, WAS, HAS, HAVE, HAD, DO, DOES, DID, BE, BEEN,  BEING, ARE, WERE, CAN, COULD, SHALL, SHOULD, WILL, WOULD, MAY, MIGHT, MUST,  NEED, KEEP, KEPT, USED TO, OUGHT TO, GOING TO, DARE, NEVER   As  we already explained a verb cannot stand lonely, one auxiliary must ...