English Review of Modal Verbs “can” and “should”

This review focuses on the modal verbs “can” and “should.” Other modal verbs will be covered in a later course.

The modal verbs “can” is used to talk about ability, ask for or give permission, or to make polite requests. The subjunctive form of “can” is “could,” which is used when wanting to be extra polite when making requests or to discuss something that is possible.

Examples:
Harold can read very fast.  (ability)
Sara, you can borrow my car if you like.  (permission)
Can I have a latte, please?  (polite request)
Could I ask you for a favor?  (very polite request)
We could go to the Italian restaurant, or we could get sushi.  (possibility)

“Should” is used to give advice, make recommendations, and discuss obligation, probability, and expectation. Here are some examples of each:

You should eat healthier food.  (advice)
You should try out the new Thai restaurant.  (recommendation)
I should study for the test.  (obligation)
The bus should be leaving soon.  (expectation)
Mary should be fine with chocolate ice cream.  (probability) 

“Should” is also a subjunctive verb, and should not be interpreted as stating a fact.