Since the verb is the structural core of every sentence, verbs that carry much of a writer's meaning make prose efficient and emphatic. This is why you are asked to recognize verbs. Furthermore, verbs express information about time and other issues such as habitual action, continuing action, obligation, ability, and possibility. The English verb system employs many helper verbs, called auxiliaries, to add to our sentences these "colors" or "flavors" as well as fine discriminations of time.
This lesson asks you to learn to recognize the following auxiliary verbs:
have (has/had/having)
be (am/is/are/was/were/being/been)
do (did/done/doing)
The modal verbs are a sub-group of auxiliaries:
shall/should
will/would
can/could
may/might
And then there is a miscellaneous assortment of auxiliaries that end in to so as to connect with the infinitive form of verbs to express many of the same ideas other auxiliaries express, for English is characterized by astonishing redundancy and variety.
have/has to
ought to
used to
am/is/are/was/were supposed to
am to/is to/etc.
am . . . going to