Modals - 30 items

Modal Verbs
Auxiliary verbs that express possibility, ability, permission, obligation, or certainty.

n

Auxiliary Verbs
Helping verbs that support the main verb to add meaning.

n

Base Verb Rule
Modals are always followed by the base form of a verb (e.g., can go).

n

No Tense Inflection
Modals do not change form (e.g., he can, not he cans).

n

No Infinitive Form
Modals cannot be used with “to” (e.g., to must).

No “Do” Support
Questions and negatives do not use do (e.g., Can you swim?).

Direct Negatives
Add not to form negatives (e.g., should not).

Question Inversion
Modal comes before the subject in questions (e.g., Should we go?).

Modals of Ability
Express capability (e.g., can, could).

General Past Ability
Could is used for general ability in the past.

Specific Past Ability
Was/were able to is used for specific successful actions.

Modals of Possibility
Express likelihood (e.g., may, might, could).

Degrees of Probability
Different modals show different levels of certainty (e.g., must = very likely).

Modals of Certainty
Used for logical conclusions (e.g., must be, can’t be).

Modals of Permission
Used to ask/give permission (can, may, could).

Formal vs Informal Permission
May is formal; can is informal.

Modals of Obligation
Express duty or necessity (must, have to).

Internal vs External Obligation
Must = internal; have to = external.

Prohibition
Must not means something is forbidden.

No Necessity
Don’t have to means something is optional.

Modals of Advice
Used to recommend actions (should, ought to).

Ought To
A more formal way to express advice.

Modals of Request
Used to ask for help politely (can, could, would).

Politeness Levels
Would is more polite than could, which is more polite than can.

Modals of Suggestion/Offer
Used to suggest or offer (shall, would).

Perfect Modals
Modal + have + past participle (e.g., should have studied).

Must Have
Expresses strong certainty about the past.

Might/May Have
Expresses possibility in the past.

Could Have
Expresses missed opportunity in the past.

Common Errors with Modals
Include double modals, wrong verb form, and incorrect past usage.