Modals are helping verbs (meaning they precede other verbs) used to indicate permission, possibility, obligation, advice, ability, prohibition, requests, and preference.
So when might you use them in academic writing? They often appear in research papers to make a suggestion, prediction, or ask a question.
Common modal verbs:
Permission: Can I take your sister to the dance?
Possibility: We might go to a movie tonight if you’re interested in coming along.
Obligation: Researchers must further review the study.