Modals – Examples and Explanation
Modals are auxiliary verbs used most often in making requests and giving instructions. They must be followed by the base form of the verb (modal + base verb; i.e. must read, can buy, etc.).
Example: Dominique can read a five-hundred page novel in four hours.
The nine most commonly used modals are the pairs: can/could, will/would, shall/should, may/might, and must (which has no pair).
In some cases the second modal in the pair is used to refer to the past (i.e. could have gone).
Example: Glenda could read when she was three years old.
Usually to refer to the past, you must use the modal followed by a perfect auxiliary tense.
Example: If you had questions, you should have gone to your teacher.
Note: “Must” uses “had to” for its past tense:
Example: We must get to the store by 5 p.m. We had to get to the store by 5 p.m.
In most cases, modals usually refer to the present or future.
Example: If you have any questions, you should go to your teacher.
When making requests, using the past form of the modal pairs does not change the tense but instead causes the request to sound more polite because it is less direct. Using different modals can also change the force of a request: