Modal auxiliary verbs 
The grammar of modal auxiliary verbs. 
Discus the following questions with your partner.
1	There are 10 modal auxiliary verbs in English. What are they?
2 	How are modal auxiliary verbs grammatically different from other verbs? 

3	Write a short, simple definition for the following verbs :
e.g.	speak : use your mouth and vocal chords to communicate in a language.
eat
walk
can
should
4 	How do you form the past tense of a modal auxiliary verb? 
Example. 
I can drive a car. (present)
When I was a child I _____________________ swim (past)
'Can you speak French' (direct speech, present tense)
I asked him if he _____________ speak French. (reported speech, past tense)
I must go to the bank this afternoon. (present)
I _____________ to go to the bank yesterday afternoon. (past)
It may rain later (future)
He may be in the kitched (present)
How do we put may in the past?
He ___________ (may / go) home.
(i.e. I think maybe he went home)
How can you make a modal auxiliary verb the subject of a sentence? 
Example :
Verb : to smoke
If you smoke you can get ill.
Smoking is bad for you 
Modal : can
I can use a computer. I think this is necessary to get a good job nowadays. 
________________________a computer is necessary to get a good job nowadays. 

Answers

1	There are 10 modal auxiliary verbs in English :
	can   could   may   might   shall   should   will   would   must   ought

2	Modal auxiliary verbs have no infinitve, gerund or past participles. 
	Most do not have a past tense and so other forms are necessary to express thepast
	However, when used to express ability, could is the past of can.
	When used to talk about the future, would is the past of will.

4	When I was a child I could swim (past)
	I asked him if he could speak French. (reported speech, past tense)
	I had to  go to the bank yesterday afternoon. (past)

	He may have gone (may / go) home.
	The ability to use a computer is necessary to get a good job nowadays.