Lesson 10: modal verbs

Should.

Should is used to express obligation or necessity where there is a choice.

Examples: Positive.

David has a lot of spare time. He should do charity work

Eliza loves reading. She should go to the library.

Examples: Negative.

Ricardo hates the dark. He shouldn´t put his light out at night.

Lilia isn´t very sick. She shouldn´t complain so much.

Would.

Modal auxiliary verb + be + infinitive ending-ing is used to speak about obligation in the present and future:

Example:  positive.

He would be driving the van now but it broke down yesterday.

They would be celebrating today if they had won the match.

Negative:

Amanda wouldn´t be sad if you weren´t angry with her.

Phil wouldn´t like to travel all the way to the America without me.

Ought to.  

Ought to is used in the same way as should but nowadays only for positive meanings.

Tony is a great singer. He ought to sing on X-factor.

Darren is a very good listener. He ought to be a councilor.