1. They didn't have chemistry yesterday.

2. We often speak English with our teacher and friends at school.

3. Her husband often pumps the water into the plot of land after finish ploughs it.

4. They never go to school last summer.

B:

1. Mary is satisfied with what she does.

2. We have been writing to each other in the past two years.

3. Bill usually have dinner on the weekend with his family.

4. I have allowed to hang out with my friends by my mom.

 Remember to check my answers before writing it. It's might wrong.

=>
IV/
Part A/
1. They did not have chemistry yesterday. 
2. We usually speak English with our teacher and friends at school. 
3. Her husband often pumps water into their plot of land after he finishes ploughing it. 
4. They have never gone to school since last summer. 
Part B/
1. Mary is satisfied with what she does. 
2. We haven't written to each other for two years. 
3. Bill usually has dinner at home with his family on the weekend.  
4. I was allowed to go out with my friends by my mother.