English Modal Verbs and Relative Clauses Mastery

Modal Verbs for Ability and Permission

CAN: We use the modal verb can to talk about ability in the present.

• Danny can climb mountains and run marathons.

CAN and MAY: We also use the modal verbs can and may to talk about permission in the present. The modal verb may is used in slightly more formal situations.

• Can we go?
• May I have another drink?

Could, Be Able To, and Allowed To

COULD: We use the modal verb could to talk about ability in the past and in the conditional form.

• When he was a child, he could ski really well.

BE ABLE TO: Used to express ability.

ALLOWED TO: Used to express permission.

Obligation, Prohibition, and Recommendations

MUST: Used to talk about obligation.

• I must finish this essay by Monday.

MUSTN'T: Used to talk about prohibition.

• You mustn't try too hard.

NEEDN'T, DON'T NEED TO, DON'T HAVE TO: Used when there is no obligation.

• You needn't get up before eleven o'clock.
• We don't have to wear a school uniform.

OUGHT (NOT) TO and SHOULD (SHOULDN'T): Used for recommendations.

• Candidates ought to/should be friendly and outgoing.

Possibility and Logical Deductions

MAY, MIGHT, COULD: Used when something is possible.

• It may be time for Linda to go.
• They might choose Danny.
• They could be on the train now.

MUST, CAN'T: Used for logical deductions. Must is used when something is true; can't is used when we are certain something is impossible.

• It must be quite late, because it's getting dark.
• That can't be true.

Modal Verbs in the Past

MUST HAVE + PAST PARTICIPLE: Used for certainty or to make a logical deduction about the past.

• Danny must have felt disappointed when he didn't win the competition.

CAN'T HAVE + PAST PARTICIPLE: Used to express an impossibility in the past.

• She can't have passed the exam—she didn't study at all.

MIGHT/MAY/COULD HAVE + PAST PARTICIPLE: Used to express a possibility in the past.

• They might not have/may not have received our message about the party.

COULD HAVE + PAST PARTICIPLE: Used for an alternative past action, even though it is now too late.

• The government could have acted more quickly.

SHOULD HAVE: Used to wish something had happened in the past (but it didn't happen).

• Linda should have made more friends.

SHOULDN'T HAVE + PAST PARTICIPLE: Used to wish something had not happened in the past (but it did happen).

• Linda shouldn't have talked so much.

Relative Clauses and Pronouns

• WHO: Used for people.
• WHOM: Used for people (often in formal contexts).
• WHOSE: Used for possession. (e.g., That's the boy whose mobile was stolen yesterday.)
• WHICH: Used for things.
• WHERE: Used for spaces or places.
• WHEN: Used for time.

Defining and Non-Defining Relative Clauses

Defining relative clauses: These are necessary to provide essential information.

• That's the boy who Bea doesn't like.

Non-defining relative clauses: These provide extra, non-essential information. They cannot use that.

• Zain Hasan, who was last year's winner, is entering the competition.