Each sentence below contains an error. Underline it and write the correct answerin the space provided. 
1. I have learnt how swim since 2010.
2. She has worked for this bank since she leaves university.
3. What sweet voice you have!
4. I go to the school library to borrow books twice.
5. Could you tell me the way to the post office ?
6. I received a letter to my friend last week.
7. I have gone to Singapore three times.
8. My brother can’t swim, so he is afraid of water.
9. Don’t eat toomuch salt because it is not good to you.
10.- “Which is the most expensive city in the world ?” – “ I think it’s Tokyo.”