Indicates a strong obligation or necessity. Example: "You [must] submit your report by the deadline."
Suggests a recommendation or advice. Example: "You [should] proofread your work before submitting it."
Denotes the ability or possibility to do something. Example: "I [can] speak three languages fluently."
Implies permission or a possibility. Example: "You [may] use this conference room for your meeting."
Indicates a slight possibility or uncertainty. Example: "I [might] attend the party if I'm not too busy."
Mastering modal verbs will help you express necessity, possibility, advice, and more effectively.