Can:

• Usage: Signifies ability, permission, or possibility.

• Example: "I can swim."

Can't:

• Usage: Indicates a lack of ability or permission.

• Example: "I can't speak French."

Should:

• Usage: Expresses advice, recommendations, or obligation.

• Example: "You should exercise regularly."

Shouldn't:

• Usage: Advises against or indicates a lack of recommendation.

• Example: "You shouldn't eat too much sugar."

Must:

• Usage: Implies a strong obligation or necessity.

• Example: "Students must attend the lecture."

Mustn't:

• Usage: Asserts a prohibition or a strong necessity not to do something.

• Example: "You mustn't smoke here."

Could:

• Usage: Represents past ability, polite requests, or hypothetical situations.

• Example: "I could solve the problem."

Couldn't:

• Usage: Denotes a lack of past ability or inability to do something.

• Example: "I couldn't find my keys."

Would:

• Usage: Used for polite requests, expressing preferences, or hypothetical situations.

• Example: "Would you pass me the salt?"

Wouldn't:

• Usage: Expresses a refusal, reluctance, or negation of a hypothetical situation.

• Example: "He wouldn't apologize."