Sure, here are the completed sentences:

1. I usually **go** (go) swimming on Saturdays.

2. Amy **is sending** (send) an email to Holly at the moment.

3. People in China never **eat** (eat) with a knife and a fork.

4. The waitress always **brings** (bring) the bill immediately.

5. Jamie's on the phone. He **is talking** (talk) to Eric right now.

6. We sometimes **play** (play) football after school.

7. I **am doing** (do) my homework right now.

8. You rarely **make** (make) me a birthday cake.

9. They always **eat** (eat) breakfast.

10. Today Sidney **is running** (run) in a race.

11. It **is** (be) my birthday today.

12. I **do not walk** (not walk) to school every day.

13. Mum **is talking** (talk) on the phone right now.

14. Tanya and her sister **are staying** (stay) with us today.

15. Usually, our teachers **do not give** (not give) us much homework.

16. I **am learning** (learn) to play tennis in school at the moment.

17. Mum **is not writing** (not write) an email right now.

18. He **is** (be) in the football team this year.

19. We **do not go** (not go) on a summer holiday every August.

20. Susan **has** (have) homework at weekends.