Early in your English course, you learn words like will, can, may, would, could, should, must or might. These words are called modals and they are very easy to use. All you have to do is to make a little space between the subject and the verb and place your modal there. They are all used the same way.
George should do exercise.
Martha can speak Italian and French.
We may go on vacation next month.
Susan must decide if she buys the house or not.
I would help you but I really can’t.
The children might need a few extra math lessons.
Notice that the main verb never changes, which makes the use of modals a simple thing. The only thing that you have to make sure of is the concept behind each modal. Some modals have a single concept and others have a double concept.
Here you have a video we made about this subject.
I strongly recommend that you do a little research on this topic. Find out how to use modals in the interrogative and the negative forms. You may also want to know how to use contractions.
And remember, if you study modals, it may take you one or two days; however, it will definitely change your current understanding as well as your English expression.