2. PRESENT ABILITY Can or be able to expresses ABILITY in present. - I can (am able to) speak English, but I can’t (am not able to) speak French. - I can (am able to) speak English, but I can’t (am not able to) speak French. - A cheetah can run fast, but it can’t fly. - A cheetah can run fast, but it can’t fly.

3. PAST ABILITY Could or was/were able to expresses ABILITY in the past. - I could (was able to) run very fast when I was a child. - I could (was able to) run very fast when I was a child. - She was a good swimmer when she was a child. She could (was able to) swim faster than all the children. - She was a good swimmer when she was a child. She could (was able to) swim faster than all the children.

4. was/were able to/managed to do sth. To express managing something that is difficult in the past was/were able to is used. - The quiz was very difficult yesterday, but I was able to get a high grade. - The quiz was very difficult yesterday, but I was able to get a high grade. (I managed to get a high grade although the quiz was difficult.) (I managed to get a high grade although the quiz was difficult.)

5. PRESENT POSSIBILITY May/Might/Could is used to express POSSIBILITY in present. - Why is Peter at home today? - Why is Peter at home today? I don’t know. He may/might/could be ill today. I don’t know. He may/might/could be ill today.

6. PAST POSSIBILITY May/Might/Could + have V3 is used to express POSSIBILITY in the past. - I can’t find my grammar book. I don’t know where I left it. - I can’t find my grammar book. I don’t know where I left it. I may/might/could have left it in the classroom or I may/might/ could have left it on the bus. I may/might/could have left it in the classroom or I may/might/ could have left it on the bus.