MODALS SHOULD AND MUST

MODALS MUST AND SHOULD

We use must / should + infinitive to talk about obligation, things that are necessary to do, or to give advice about things that are a good idea to do. Must is used for obligation. They are both followed by the infinitive. I must go now.

What is the difference of should and must?

The words “should” and “must” are modal auxiliary verbs or simply modals. They provide information about the function of the main verb following it. Both “should” and “must” are similar in meaning except that “must” is a much stronger word as compared to “should.” 

1) Should 

Should  is used to give advice ,to make recommendations or to talk about what we think is right or wrong.

You should eat more slowly.

negative form  :shouldn't

You shouldn't  work so much

2) Must

Must is used to talk about an obligation or  probability .

positive form : must

You must do your homework.

Negative  form : mustn't

mustn't  is used  to forbid something ,it is forbidden, it is foolish to do it.

You mustn't be late.