can, could, may, might, may have, could have, can't have
Ability and possibility — can / could / may / might; past possibility with may have and could have; sure it didn't happen with can't have.
A — Sample sentences
Words like boil, fry, grill, roast, chop, peel, ingredients, recipe, spicy, bitter, and fresh.
1) can / could — ability and polite requests
can = present ability; could = past ability or a polite request.
- She can chop vegetables very quickly.
- He could not boil an egg when he was a student.
- Can you pass the salt, please?
- My grandmother could bake bread without a recipe.
2) may / might — present possibility (maybe)
may and might + base verb = perhaps, maybe. Might often sounds a little less sure than may.
- I may cook pasta tonight — I haven't decided yet.
- The sauce might be too spicy for the children.
- We may grill the fish if the weather is good.
- There might be some fresh bread left in the kitchen.
3) may have / might have / could have — past possibility
Something was possible in the past — we are not sure if it happened. May have and might have are common in careful speech and writing.
- He may have forgotten to add the spices.
- They might have grilled the fish instead of frying it.
- She could have used fresh vegetables, but she chose frozen ones.
- We may have roasted the chicken for longer — it was a bit dry.
4) can't have / couldn't have — impossible past deduction
We are sure something did not happen in the past.
- He can't have eaten the cake — I can still see it on the plate.
- She couldn't have peeled all those potatoes alone in five minutes.
- They can't have followed the recipe — the soup tastes completely wrong.
- You couldn't have burnt the rice — the pan is still clean.
The rest of this lesson is in the General English course:
- B — Quick reference
- C — may / might vs can / could
- D — to be able to
- be able to — the forms
Try it: can, could, may, or might?
Choose the best form for each sentence.
- My sister ___ bake excellent bread — she does it every week.
(a) can (b) may (c) might have - The curry ___ be too hot for your brother.
(a) can (b) might (c) can't have - ___ you chop the onions for the soup, please?
(a) May (b) Could (c) Might - We ___ order seafood tonight, but we haven't chosen a restaurant yet.
(a) may (b) could have (c) can't
Check your answers in the course — it marks them instantly. This is one of the unit's 5 exercises; the other 4 are in the General English course too.
Practise this unit in the course →