Exercise 1

3. can read an English newspaper...could (read one)

4. couldn't read an English novel...can't (read one)

5. can speakon the phone...couldn't (speak on the phone)

6. couldn't speak with a group of people...can (speak with a group of people)

7. could write an email...can (write one)

8. Before the course, he couldn't write a business letter, and he still can't (write one)

9. Now he can order a meal in English, and he could (order a meal in English) before too.

10. Now he can go shopping, and he could (go shopping) before too.

 Exercise 2

2. A: What languages can you speak?

3. A: Could you speak Spanish when you were a child?

   B: No, I couldn't.

4. A: Could you speak French?

   B: Yes, I could.

5. A: Before you came here, could you understand spoken English?

   B: No, I couldn't

6. A: Can you understand song lyrics?

   B: Yes, I can.

7. A: Before this course, could you write a business letter in English?

   B: No, I couldn't.

8. A: Could you drive a car before you came here?

   B: No, I couldn't.

9. A: Can you drive a car now?

   B: No, I can't.

10. A: Can you swim?

     B: Yes, I can.

11. A: Could you surf before you couldn't do before?

     B: can do ... couldn't do  

Exercise 3

2. can damage

3. can recover

4. can't survive

5. can lose

6. can listen

7. can...do

8. can understand

9. can't leave

10. can't be

Exercise 4 

2. are able to interpret

3. are not able to distinguish

4. are not able to understand

5. are able to hear

6. are able to get back

7. are able to read

8. is not able to recognize

9. is not able to work

10. are able to communicate

 Exercise 5

3. How will...be able to see

4. Will...be ableto hear

5. No, you won't.

6. How will...be able to solve

7. Will...be able to enjoy

8. Yes, you will.

 Exercise 6

2. could read

3. couldn't accept

4. was able to accept

5. could see

6. will...be able to do

7. can do

8. can do

9. can speak

10. was able to achieve

11. will be able to get

12. can read

13. can change

14. can do

 Exercise 7

can't --> couldn't

wasn't able understand --> wasn't able to understand

could leave --> was able to leave

can to understand --> can understand

explains --> explain

can speak --> will be able to speak

can't understand --> couldn't OR wasn't able to understand 

can to understand --> can understand

can do --> 'll be able to do