MUST/HAVE TO/SHOULD- INTERACTION

MUST/HAVE TO/SHOULD (OBLIGATION)

HOW DO WE USE THEM?

AFFIRMATIVE STRUCTURES

• MUST+ INFINITIVE VERB. For example: I must get up at 5 tomorrow

• HAVE TO+ INFINITIVE VERB. For example: I have to start work early

• SHOULD+ INFINITIVE VERB. For example: You should do your work properly

NEGATIVE STRUCTURES

• MUSTN'T+INFINITVE VERB. For example: You mustn't do that!

• DON'T HAVE TO. For example: You don't have to worry

• SHOULDN'T+ INFINITIVE VERB. For example: You shouldn't smoke here

INTERROGATIVE STRUCTURE

• MUST+SUBJECT+INFINITIVE VERB. For example: Must you go so early?

• DO/DOES+SUBJECT+HAVE TO+INFINITIVE VERB. For example: Do you have to go so early?

• SHOULD+ SUBJECT+INFINITIVE VERB. For example: Should you go quickly?

USES

• We use MUST and HAVE TO to talk about obligations. These things are necessary or important. MUST is often used for a personal obligation (something we have decided for ourselves that we must do). For example: We must give up eating chocolates

• MUST is also used in written rules. For example: All applicants must provide proof of identity

• HAVE TO is used for external obligation. For example:We have to wear uniforms (It's a company rule)

• SHOULD indicates obligation in the sense of duty or correctness, often when criticizing another person. For example: You should be at work now