Modal Verbs: ability, obligation, advice, permission
الأفعال الناقصة
can, could, must, have to, should, may, might — meaning and correct form.
Step 1 — Learn
Concept, rules, model examples and the mistakes STEP repeats every year.
Concept
Modals are followed by the base verb with no to and no -s. Each modal expresses a specific meaning: ability, obligation, prohibition, advice, permission or possibility.
الأفعال الناقصة يتبعها الفعل في صيغته الأساسية بلا to وبلا s، ولكل منها معنى محدد.
Rules & forms
Ability: can / could / be able to
- • She can swim.
- • He was able to finish it.
Obligation: must / have to · Lack of obligation: don't have to
mustn't تعني المنع، وdon't have to تعني عدم الإلزام.
- • You must wear a seatbelt.
- • You don't have to come.
Prohibition: mustn't / can't
- • You mustn't use your phone in the exam.
Advice: should / ought to / had better
- • You should revise tonight.
Possibility: may / might / could
- • It may rain later.
Common mistakes & STEP traps
❌ He can to drive.
✅ He can drive.
No to after a modal.
❌ She musts study.
✅ She must study.
Modals never take -s.
❌ You mustn't come if you are busy.
✅ You don't have to come if you are busy.
Mustn't means prohibition, not lack of obligation.
❌ I will can help you tomorrow.
✅ I will be able to help you tomorrow.
Two modals cannot follow each other.
Step 2 — Practice
Sentence completion, error recognition and usage discrimination. Feedback appears only after you answer.
Modal Verbs: ability, obligation, advice, permission practice
Score 0/10Question 1 of 10 · Form
He can ______ three languages.
Step 3 — STEP test
Exam-style multiple choice with scoring, percentage and a review of everything you missed.
Modal Verbs: ability, obligation, advice, permission STEP test
Score 0/10Question 1 of 10 · STEP
Passengers ______ fasten their seatbelts during take-off.