Expressing Ability, Obligation, and Advice | English Grammar Guide for French Students

• 1 Do not change form for different subjects (I can, you can, he can)
• 2 Do not use "to" before the main verb (can go, not "can to go")
• 3 Form questions by inversion (Can you? not "Do you can?")
• 4 Form negatives by adding "not" (cannot, should not)

1 Can: Present ability: "I can swim"
2 Could: Past ability: "I could run fast when I was young"
3 Be able to: More formal alternative: "I am able to solve this"
4 Will be able to: Future ability: "I will be able to drive next year"

• 1 "She can speak four languages fluently."
• 2 "When I was younger, I could run a marathon."
• 3 "They are able to finish the project on time."
• 4 "After training, he will be able to lift heavier weights."

1 Must: Strong personal obligation: "You must finish your homework"
2 Have to: External obligation: "I have to go to work"
3 Need to: Necessity: "We need to prepare for the exam"
4 Should: Moral obligation: "You should help others in need"

• 1 "Students must attend all classes." (school rule)
• 2 "I have to pay my taxes." (legal requirement)
• 3 "You need to drink more water." (health necessity)
• 4 "We should protect the environment." (moral duty)

1 Should: General advice: "You should eat more vegetables"
2 Ought to: Formal advice: "You ought to see a doctor"
3 Had better: Strong advice with warning: "You had better study for the test"
4 Would recommend: Formal recommendation: "I would recommend this book"

• 1 "You should exercise regularly." (health advice)
• 2 "He ought to apologize for his mistake." (formal suggestion)
• 3 "We had better leave now." (urgent advice)
• 4 "I would suggest taking a break." (polite advice)

Modal	Function	Strength	Example
Can	Ability	Moderate	"I can speak English"
Could	Past Ability	Weak	"I could run fast"
Must	Strong Obligation	Very Strong	"You must be quiet"
Have to	External Obligation	Strong	"I have to work"
Should	Advice/Obligation	Moderate	"You should study"
Had better	Urgent Advice	Strong	"You had better leave"

1 Could have: Past ability that wasn't realized: "I could have passed"
2 Should have: Past advice/regret: "You should have studied"
3 Must have: Logical deduction about past: "He must have left"
4 Need not have: Unnecessary past action: "You need not have worried"

1 First Conditional: "If you study, you can pass"
2 Second Conditional: "If I were rich, I should travel"
3 Third Conditional: "If I had studied, I would have succeeded"
4 These combine modals with conditional structures for complex expressions

• 1 Confusing "must" and "have to" for source of obligation
• 2 Using "can" for future ability instead of "will be able to"
• 3 Mixing up "should" (advice) with "must" (obligation)
• 4 Forgetting that modals don't take "to" before main verbs

1 ✓ Correct: "I can swim"
2 ✗ Incorrect: "I can to swim"
3 ✓ Correct: "You should rest"
4 ✗ Incorrect: "You should to rest"

1. I _______ speak French fluently. (ability)

2. When I was young, I _______ run very fast. (past ability)

3. After training, she _______ lift heavier weights. (future ability)

4. Students _______ complete their assignments. (strong obligation)

5. I _______ go to work today. (external requirement)

6. We _______ help those in need. (moral obligation)

7. You _______ eat more vegetables. (health advice)

8. He _______ apologize for his mistake. (suggestion)

9. We _______ start preparing for the exam now. (recommendation)

1. can

2. could

3. will be able to

4. must

5. have to

6. should

7. should

8. should

9. should

1 English: Uses modals (can, must, should) as auxiliaries
2 French: Uses conjugated verbs (pouvoir, devoir, falloir) with subject agreement
3 English: No subject agreement needed for modals
4 French: Requires agreement patterns for gender and number

1 Can: Pouvoir (je peux, tu peux, il peut)
2 Must: Devoir (je dois, tu dois, il doit)
3 Should: Devoir (more formal) or "il faut" (impersonal)
4 Have to: Devoir (external obligation) or falloir (impersonal)

1 Ability: "Can" sounds like "capacity" (ability)
2 Obligation: "Must" is stronger than "have to" (internal vs external)
3 Advice: "Should" suggests a recommendation
4 Practice regularly: Use modals in daily conversations

• 1 Create daily scenarios using each modal category
• 2 Practice forming questions and negatives with each modal
• 3 Read English texts to see natural usage patterns
• 4 Focus on context to determine the correct modal

• Ability: Can, could, be able to express capability
• Obligation: Must, have to, need to express necessity
• Advice: Should, ought to, had better express recommendations
• Each modal has specific strength and usage contexts

Remember: Can = Ability, Must = Obligation, Should = Advice!

• Start with basic ability expressions
• Gradually add obligation and advice modals
• Focus on context to choose the right modal