What are the twelve functions of modal verbs?

Following the last three chapters on this topic which have covered the concepts, importance and forms of modal verbs within an academic context, this final chapter now provides detail about the many functions of these special auxiliary verbs. Twelve functions across attitudinal and communicative categories have been isolated, with example sentences for each possible modal verb being provided to help guide students when using modality in their own speech or writing. Please note that sometimes in the below examples it is the sentence function itself, such as whether a declarative statement or interrogative question is used, that may determine the appropriate modal verb.

Attitudinal Functions

Ability (be able to / can / could)

“I can do my presentation on Monday.”

“I could never come first in my class.”

“I am able to pass the exam provided I study.”

Deduction (must / ought to / should / will)

“Jack must be running a little late for class.”

“The teacher ought to be here by now.”

“She should have finished the exam by now.”

“That will probably be Sarah’s course book.”

Disapproval (dare / ought to / will)

“She wouldn’t dare be late.”

“You ought to be quiet and listen.”

“They will do things they shouldn’t be doing.”

Necessity (have to / must)

“You have to be more punctual if you wish to pass.”

“She must speak with me about her plagiarism.”

Obligation (have to / must / need / ought to / shall / should)

“You have to be at the exam hall by 9am.”

“He must not miss the deadline.”

“You needn’t email me again about this.”

“Jack ought to tell someone if he’s going to be absent.”

“You shall inform your group members about your cheating.”

“She should inform administration about her absence.”

Possibility (could / may / might)

“You could pass if you study hard.”

“He may find himself at the top of the class.”

“She might fail if she’s not careful.”

Communicative Functions

Advising (had better / ought to / should)

“You had better inform administration about your sickness.”

“Tell her that she ought to message me next time.”

“You should really take a day off to relax.”

Inviting (might / would)

“Might you be interested in submitting your assignment early?”

“Would you like to join our society?”

Offering (may / might / shall / would)

“May I help you in any way?”

“Jack, might you be able to answer that question?”

“Michael shall help you with your work.”

“Would you like any assistance, or are you OK?”

Permitting (can / may)

“You can go to the toilet.”

“You may leave class early if you really need to.”

Requesting (can / may / would)

“Can I please leave class early as I have a doctor’s appointment?”

“May I borrow your calculator for ten minutes?

“Would you mind if I opened the window?”

Suggesting (could / shall / should)

“You could try using some online resources too.”

“Shall we start class a little late tomorrow?”

“Should we skip this chapter? It’s a little boring.”