Modals
-are auxilliary verbs performing specefic functions like:
*Must-expresses obligation
*Need to-indicates necessity
*Should and ought to-expresses sense of obligation to do or to become sonething
*Shouldn't or should not have or ought not-indicate prohibition, or disapproval of something that was done in the past.
Auxiliary Verbs
-are function words, a type of closed class which is constituted of words that have a grammatical function opposed to content words, which are an open class of lexical words.
-is used to add functional or grammatical content to the information expressed by another verb, considered to be the main verb. Auxiliary verbs are also called helping verbs.
Examples:
* I am writing a book.
* He has done the work.
* We will be there in an hour.
* Would you help me with this homework?
* Can you open the door?
* Did you visit New York last holiday?
*Do you like chocolate?
* They must gey there on time.
The 23 auxiliary verbs
Am is are
Was were
Has have had
Do does did
Will would
Shall should
Can could
May might must
Be been being
