Modal verbs

The modal verbs include can, must, may, might, will, would, should. They are used with other verbs to express ability, obligation, possibility, and so on. Below is a list showing the most useful modals and their most common meanings:

Modal       Meaning                                   Example

can            to express ability                         I can speak a little Russian.

can            to request permission                  Can I open the window?
may           to express possibility                   I may be home late.
may           to request permission                  May I sit down, please?
must          to express obligation                   I must go now.
must          to express strong belief               She must be over 90 years old.
have to      to express obligation                   Children have to go to school.
should       to give advice                             You should stop smoking.
would        to request or offer                      Would you like a cup of tea?
would        in if-sentences                            If I were you, I would say sorry.