Mastering English Modal Verbs: Can, Could, Must, and Ability

1. Can / Be Able To: Expressing Ability

• Gary has traveled extensively and can speak five languages.
• I haven't been able to sleep very well.
• Nicole can drive, but...
• I used to be able to stand on my head.
• I can't understand Mark. I've never been able to understand him.
• I can't see you on Friday, but I can meet you on Saturday.
• Ask Katherine about your problem. She might be able to help you.

2. Can, Can't, Could, Couldn't: Present & Past Ability

• I'm afraid I can't come to your party next week.
• When Dan was 16, he could run 100 meters.
• Are you in a hurry? No, I can wait.
• I was feeling sick yesterday. I couldn't eat anything.
• Can you speak a little louder? I can't hear you very well.
• You look tired. Yes, I couldn't sleep last night.

3. Could, Couldn't, or Managed To: Past Achievement

• My grandfather could...
• I looked, but couldn't...
• They didn't want to, but managed to...
• Laura had hurt herself, so she couldn't...
• I ran my first marathon and managed to...
• I looked very carefully, and managed to...
• I wanted to buy, but managed to...
• My grandmother could...
• A girl fell, but could...
• I had forgotten, so I couldn't...

4. Could vs. Can: Correcting Common Errors

• The story could be true.
• It's a nice day. (OK)
• I'm so angry, I could...
• If you're hungry... (OK)
• It's so nice here, we could...
• Where's my bag? (OK)
• Peter is a keen musician. (OK)
• I need to borrow... (OK)
• Be careful! You could...

5. Could / Could Have + Verb: Possibility & Regret

• What shall we do? We could have...
• I spent a very boring evening. I could have gone...
• Have you seen the job advertisement? You could apply.
• How was your exam? You could have called...
• I got very wet. I could have called...
• Where shall we meet? We could go...

6. Couldn't / Couldn't Have + Verb: Impossibility

• I couldn't live in a big city.
• We had a really good time. It couldn't have been better.
• I couldn't wear that hat.
• We managed to find the house, but we couldn't have found it without the map.
• Paul has to get up early. He couldn't get much sleep.
• The staff at the hotel couldn't have been more helpful.
• I tried to phone, but you couldn't have come to the phone.

7. Modal Verbs: Completing Phrases

• I've lost my keys. I must have dropped them.
• Their house must be very old.
• Sarah knows a lot about film. She must have gone to film school.
• I left my bike here. It might have been stolen.
• How old is Ted? He must be around 40.
• I didn't hear the phone. I must have been asleep.
• You're going on holiday. You must have been working very hard.
• The police have closed the road. There must have been an accident.
• I'm sure you must have heard the news.
• There is a man. He must have been following me.

8. Must Have & Can't Have: Deductions About the Past

• We went to their house, but they weren't there. They must have gone out.
• Sarah hasn't replied. She can't have got my message.
• The jacket looks expensive. The jacket you bought must have been very expensive.
• I haven't seen our neighbors for a while. They must have gone away.
• I can't find my wallet. I must have left it in the restaurant last night.
• Amy was in a very difficult situation. It can't have been easy for her.
• There was a man standing outside. He must have been waiting for somebody.
• Rachel did the opposite of what I asked. She can't have understood what I said.
• When I got back home, there was a mess. My neighbor must have had a party.
• The light was red. The driver can't have seen the red light.