AUXILIARY VERBS

          

Category 1:  be, have, do

                      

These forms of to be, to have, and to do are used before the main verb.

Their purpose is to change time or emphasis.

                   

Unlike other structure words, these auxiliary verbs

1.  can have inflectional endings (-s, -ing, -ed, -en)

2.  can also function as main verbs.

             

         

Category 2: Modal auxiliaries

The list below shows all of the modal auxiliaries:

Present	can	may	will	shall	must
Past	could	might	would	should	-------

                                   

                                         

Unlike the auxiliaries  be, have, and do, modal auxiliaries

1. do not use inflectional endings (-s, -ed, -ing, -en)

2. cannot function as main verbs.

When a verb phrase uses both kinds of auxiliary verbs, the modal auxiliary alwaysprecedes the be, have, or do auxiliary.