1 Write affirmative (W) and negative (X) sentences with can.
1 Jamie / run fast. (W)
Jamie can run fast.
2 My granddad / use a mobile phone.
3 They / skateboard. (X)
4 You / stay out late tonight. (X)
5 I/ski. (X)
6 She/ play the piano. )​

1 Jamie can run fast. (W)
2 My granddad can use a mobile phone. (W)
3 They can't skateboard. (X)
4 You can't stay out late tonight. (X)
5 I can't ski. (X)
6 She can play the piano. (W)

Explanation for each sentence:

1 Jamie can run fast. (W):
This sentence states that Jamie has the ability to run fast.

2 My granddad can use a mobile phone. (W):
This sentence means that my grandfather is capable of using a mobile phone.

3 They can't skateboard. (X):
This sentence expresses that they do not have the ability to skateboard.

4 You can't stay out late tonight. (X):
This sentence implies that you are not allowed to stay out late tonight.

5 I can't ski. (X):
This sentence signifies that I do not possess the ability to ski.

6 She can play the piano. (W):
This sentence states that she has the ability to play the piano.