Modal verbs are used to express concepts like ability, permission, possibility, necessity and obligation. Some common modal verbs are can, could, may, might, must, shall, should, and will. Modal verbs are followed by an infinitive without "to" and do not change form or require auxiliary verbs. They can express single concepts like possibility or double concepts like permission and probability. When referring to past ability or possibility, modal verbs are used with "have" plus the past participle form of the main verb.

1. Modal Verbs
Diego CosavalenteDiego Cosavalente
Colegio Claretiano-2015Colegio Claretiano-2015

2. What are modal verbs?
They are:
• Can
• Could
• May
• Might
• Must
• Shall
• Should
• Will
• Would

3. How do we use modals?
Example: Mary could play the piano
S
Subject
V
Verb
M
They do not accept conjugation
They do not need other auxiliary verbs

4. Form
He could play football in his youth (general ability)
Modal verbs do not have infinitives or –ing forms
Modal verbs are followed by an infinitive without to

5. Single Concept Modal
ModalModal ConceptConcept ExamplesExamples
Might Small probability I might move to Canada some day

6. Double Concept Modal
ModalModal ConceptConcept ExamplesExamples
May (1) Permission May I come in?
May (2) Good probability We may visit Mexico this summer

7. Double Concept Modal
ModalModal ConceptConcept ExamplesExamples
Could (1) Unreal Ability I could go if I had time
Could (2) Past Ability She could play the piano, not anymore

8. Modals in the Past
They are modals referred to actions that
happened in the past
MODAL + HAVE + verb in past participle

10. Modals in Past : Modal + have + past participle