Modal Verbs
by Coby Datema
1. Won't/Would not
1.1. + Refusal
2. Obligation/ Necessity
2.1. Yes
2.1.1. Mustn't
2.1.1.1. Present, prohibition
2.1.2. Must
2.1.2.1. Present only
2.1.3. Have to
2.2. No
2.2.1. Needn't
2.2.2. Don't need to
2.2.3. Don't have to
3. Advice/ the right thing to do
3.1. Should (not)
3.2. Ought (not) to
4. Ability, Possibility and Opportunity
4.1. Can
4.1.1. Present only
4.2. Be able to
4.3. Manage to
4.4. Could
4.4.1. Sometimes Could is the past of 'can', esp. with senses/ General ability in the past
4.5. Couldn't
4.5.1. Specific and general ability in the past
5. Deduction/ Certainty
5.1. Must
5.2. Can't
5.3. Should
5.3.1. Expectation
5.4. must have/ can't have/ couldn't have
5.4.1. Past
6. Permission and Requests
6.1. Can
6.2. Can't
6.2.1. No permission/ "Don't do this"
6.3. May
6.4. Could
6.4.1. Present request. Informal past permission, General
6.5. Couldn't
6.5.1. Question Tag request. Informal, no permission in the past
6.6. Be allowed to
7. Possibility/ Speculation
7.1. Could
7.2. Might
7.3. Might not
7.4. May
7.4.1. Also used for general possibility
7.5. May not
7.6. Could have/ Might have/ May have
7.6.1. Past
7.7. Can
7.7.1. General possibility only