Modal Auxiliaries

Modal Auxiliaries 

Modals (also called modal verbs, modal auxiliary verbs, modal auxiliaries) are special verbs that behave irregularly. 

They are different from normal verbs like "work, play, visit..." 

They give additional information about the function of the main verb that follows it. 

They have a great variety of communicative functions. 

Modal Verb	Functions
Will	Simple future actions for the first person- with emphasis To denote definiteness about a future action Simple future actions for the second and third person- without emphasis Decisions made or intentions expressed at the time of speaking Desire or willingness for something or someone Facts about the future Prediction regarding a future action or event Formal announcements regarding some future event A request/ a suggestion/ an order/ seeking an opinion Habits and characteristics behaviour
Shall	A simple future action for the first person- without emphasis Polite question An offer A suggestion Asking for advice Simple future actions for the second and third person- with emphasis Higher degree of formality- legal documents, minutes of the meeting  Obligation
Would	Past tense of will Past habits or characteristics Past refusal Polite request Conditional for other verbs
Should	Obligation or duty  Logical deduction Suggestion or advice Probability Conditional for the first person
Can and Could	Denote ability, knowledge or skill Seek and grant permission Make a request Make an offer/ suggestion to help
May and Might	Chance Permission Refusal to permission sought Wishes, hopes and prayers Requests Suggestions Weak possibility (might)
Must	Strong obligation Compulsion Necessity
Ought to	Moral duty Obligation (moral/ recommendation) Logical deduction
Need	Obligation (in question)
Dare	Not afraid of doing something           (used mostly in questions and negative sentences)
Needn't	Absence of obligation
Daren't	Afraid of doing something
Mustn't	Strong prohibition
Oughtn't	Prohibition