Ответ:

1. My brother is as busy as a bee. (Present Simple)

Is your brother as busy as a bee?

Who is as busy as a bee?

Is your brother or his brother as busy as a bee?

My brother is as busy as a bee, isn't he?

2. My brother has already bought a new mobile phone (Present Perfect)

Has your brother bought a new mobile phone yet?

Who has already bought a new mobile phone?

Has my brother bought a new mobile phone or a new tablet?

My brother has already bought a new mobile phone, hasn't he?

3. We walked yesterday. (Past Simple)

Did you walk yesterday?

Who walked yesterday?

Did you walk yesterday or last week?

We walked yesterday, didn't we?

4. My friend writes every day. (Present Simple)

Does your friend write every day?

Who writes every day?

Does your friend write every day or once a week?

My friend writes every day, doesn't he?

5. We read yesterday. (Past Simple)

Did you read yesterday?

Who read yesterday?

Did you read or write yesterday?

We read yesterday, didn't we?

6. I will go to school tomorrow. (Future Simple)

Will you go to school tomorrow?

Who will go to school tomorrow?

Will you go to school tomorrow or stay at home?

I will go to school tomorrow, won't I?