English modal verbs and modal expressions help us express ideas like ability, advice, obligation, probability, permission, habits, and future intentions. They allow speakers to show their attitude, possibility, or necessity without changing the main verb form. The infographic below introduces the core modal verbs and their most common meanings.
To help you understand and use them correctly, we’ve grouped modals into seven categories based on their function, not just their form. This makes it easier to learn when and how to use them naturally. You’ll find the link in the category column.
True Modals and Modals Expressions – Table
| Category | Examples |
|---|---|
| Modals of Ability | can, could, be able to |
| Modals of Advice | could, should, ought to, had better |
| Modals of Obligation & Necessity | must, have to, need to, ought to, needn’t |
| Modals of Deduction & Probability | must, might, may, could, can’t, couldn’t |
| Modals of Permission & Prohibition | mustn’t, can, could, may, might, allowed to |
| Modals of Habits | used to, be used to, get used to, would |
| Modals of Future & Intention | going to, be about to, be willing to, shall |
How Modal Verbs Behave
Modal verbs (also called ‘true modals’ or ‘core modals’) such as can, must, and should follow a few simple rules:
- They are always followed by the base form of the verb (without “to”)
→ She can drive. - They do not change form for the third person singular
→ He must finish it. (not musts) - They do not take “do/does” for questions or negatives
→ Can you help? / He mustn’t be late.
Modal verbs are defective verbs, meaning they lack full conjugation: you cannot say “I musted” or “she cans”. To express different tenses, we often rely on semi-modals.
How Modal Expressions Behave
Modal expressions (also called semi-modals, or modal-like structures) such as have to, be going to, and used to follow slightly different grammatical rules. They act like modals in meaning but behave more like regular verbs in form.
- Most include auxiliary verbs (be or have)
→ She is going to call you. - They do change for tense, person, and number
→ He has to leave. / They had to leave. - Some are followed by to + base verb, others by a gerund
→ She’s used to waking up early.
→ He needs to study.
These expressions fill in the gaps that true modal verbs cannot cover, especially for expressing past, future, and habitual actions.
This new organization makes it easier to learn how and when to use each structure. You can now explore modal verbs by function, not just grammar. To visit each section, click the links in the Category column on the table above.
Exercises to practice Modal Verbs:
EnglishPage | Ego4u1 | Ego4u2 | EnglishClassroom
Modals in the Past – Mixed: EslLounge | OxfordUP | BusinessEnglishResources | SpeakSpeak | PerfectEnglish | ToLearnEnglish | AutoEnglish | EducationQuizzes | LiveWorksheets | Apitwist | MyEnglishPages