May vs Might vs Must
Master possibility and certainty with modal verbs
Grammar Explanation
🇬🇧 English
Possibility (50%), permission (formal)
It may rain today. / May I come in?
Lower possibility (30%), past of may
It might rain later. / He said he might come.
Strong certainty (90%), obligation
You must be tired. / You must finish this.
🇫🇷 Français
Possibilité (50%), permission (formel)
Il se peut qu'il pleuve. / Puis-je entrer ?
Possibilité moindre (30%), passé de may
Il pourrait pleuvoir plus tard. / Il a dit qu'il pourrait venir.
Forte certitude (90%), obligation
Tu dois être fatigué. / Tu dois finir ça.
Probability Scale
Key Rules
✅ Correct Usage
- • It may be expensive (50% possibility)
- • It might be expensive (30% possibility)
- • It must be expensive (very certain)
- • May I help you? (formal permission)
- • You must be on time (obligation)
❌ Common Mistakes
- • He
must beat home, but I'm not sure → He may be - • You
might tofinish → You might finish - •
MustI come? → May I come? (permission) - • I
may togo → I may go
Common Mistakes to Avoid
He must be at home, but I'm not sure.
❌ Don't use "must" when you're uncertain
He may/might be at home, but I'm not sure.
✅ Correct - use may/might for uncertainty
You might to finish this later.
❌ Don't use "to" after modal verbs
You might finish this later.
✅ Correct - no "to" after modal verbs
Practice Exercises
Test your understanding with these exercises