MODAL VERBS

1. Obligation

1.1. Afirmative

1.1.1. Must (present)

1.1.2. Have to

1.1.2.1. Had to (past)

1.1.2.2. Will have to (future)

1.1.2.3. Would have to (conditional)

1.2. Negative

1.2.1. Don't have to

2. Conditional

2.1. Will

2.2. Would

3. Possibility

3.1. Could

3.2. Must

3.3. Might

4. Advice

4.1. Afirmative

4.1.1. Should

4.1.2. Ought to

4.2. Negative

4.2.1. Shouldn't

4.2.2. Oughtn't to

5. Certainty

5.1. Afirmative

5.1.1. Must

5.1.1.1. (100% sure)

5.1.2. Should

5.1.2.1. (Quite sure)

6. Ability

6.1. Negative

6.1.1. Could (past)

6.1.2. Can (present)

6.2. Be able to

6.2.1. Will be able to (future)

6.2.2. Was able to (past)

7. Permission

7.1. Afirmative

7.1.1. May

7.1.2. Can

7.2. Negative

7.2.1. Mustn't

7.2.2. Can't