Modal verbs

What is a modal verb?

(a)  

We tend to use the modal verb "Should" for recommendations.

(a)  

We use the modal verb "Have/has to" for internal obligations and expressing feelings.

(a)  

The modal verb "Can" is only used to talk about ability.

(a)  

INTERROGATIVE STRUCTURE: OUGHT TO

OUGHT TO YOU EAT THESE COOKIES?

(a)  

The modal verb "mustn´t" is used to talk about internal obligations.

(a)  

"Had better" is a modal verd to express that something is a good or bad idea.

(a)  

The modal verb "Must" is used to talk about an obligation that comes internally from ourselves.

(a)  

This sentence is correct:

My mother angrily says that I must clean my bedroom because it is a mess.

(a)  

This sentence is wrong:

My dad should take a shower because he smells very bad.

(a)