Modal verbs such as can, could, may, must are followed by the base form of another verb. They do not require auxiliary verbs and can take direct negative and question forms. Modal verbs cannot be combined with each other. Can expresses ability and permission, while must is used to talk about strong obligations and prohibitions, usually related to laws and rules. Can and must are followed by the base form of a verb without using "to". Questions and negatives are formed using can't/mustn't plus the base verb form.

1. Modal verbs
• Rules
– They are followed by a verb in the base form
• I can run very fast
– They are the same for all the pronouns
• She/they/I/ you could make it better
– They do not need auxiliars. They take direct
negative and qestion forms
• You can’t smoke here / Can you repeat that?
– They never combine with another modal verbs
• You can’t must read**

2. Can and must
Can expresses ability and permission
•I can speak English
•You can’t play the guitar
•Where can you play tennis?
•You can go out this weekend because you finished your homework
•Can I go to the toilet?
Must is used to talk about strong obligations and
prohibitions. They are usually related with laws and rules
I mustn’t speak when the teacher is speaking
She must eat more healthy food
You must go to bed now, it is very late
STRUCTURE
SUBJECT + CAN/MUST + BASE FORM OF THE VERB without to
SUBJECT + CAN’T /MUSTN’T+ BASE FORM OF THE VERB
CAN + SUBJECT + BASE FORM?

3. COUNTABLE AND UNCOUNTABLE