I need to correct the mistakes in these sentences

1. A Have you ever had an operation?
B. Yes, I had broken broke my leg two years ago.

2. A. How long was your uncle in hospital?
B. Since last Tuesday. He's coming home tomorrow.

The tense usage in the answer isn't correct given the tense used in the question. 

Your response would be correct if the question used the present perfect, as your answer shows your uncle is still in hospital, and it is therefore not a completed action.

e.g. How long has your uncle been in hospital?

Since last Tuesday. He's coming home tomorrow.

The question you posted uses the simple past. It is a completed action so therefore you need to answer with a period of time.

How long was your uncle in hospital? 

e.g. Two weeks. He got out last Tuesday.

3. You haven't taken your medicine yet. 

4. A. Have you gone to see the doctor?
B. Not yet. I'm going this afternoon.

5. I cut my finger! Have you got a plaster?

6. I have known my doctor for ten years. She's very good.

I need to correct the mistakes in these sentences

1. A Have you ever had an operation?
B. Yes, I had broken my leg tow years ago. (Two )

2. A. Hoy long was your uncle in hospital?
B. Since last Tuesday. He's coming home tomorrow. (How long)

3. You haven't taken your medicine yet.

4. A. Have you gone to see the doctor?
B. Not yet. I'm going this afternoon.

5. I cut my finger! Have you got a plaster?

6. I know my doctor for ten years. She's very good. ( I have known my doctor for ten years)