CAN means am able or to be able to.

EXAMPLE:
I can do that for you.
Can you do that for me?

MAY is used to ask politely to be premitted or allowed to do something.

EXAMPLE:
May I be excused?
You may sit there.

1. Can / May I help you?

2. He's smart, he can / may do it himself.

3. When can / may I have my dessert?

4. I can / may tell you exactly what she said.

5. He can / may speak fluent Spanish.

6. You can / may use my pen.

7. I can / may be allowed to attend the concert.

8. It's bright, can / may I see it?

9. Can / May my friend stay for dinner?

10. You can / may leave now.

11. I can / may see your point.

12. She can / may dance well.

13. Can / May you help me with my shoes?

14. Mother, can / may go out and play?