Сформулируйте общий вопрос к каждому предложению.
1) They never go to the office on foot.
2) Nick has seen your sister only once.
3) My mother prefers detective stories.
4) We are watching TV now.
5) You made a lot of mistakes in that task.
6) Tom has talked to me on this matter before.
7) The child is sleeping.
8) Her sister left for Minsk 4 days ago.

- Good morning, sir. 
- Good morning. Come in, Mrs. Volkova. Please, take a seat. Tell me, how long you were in your last job with "Pine"? 
- I worked for "Pine" for 6 years. 
- Did you hold a good post there? 
- I started as a courier but a few months later I filled the vacancy of shopassistant. I had been working as a shopassistant for 3 years when I was promoted from shopassistant to Supplies Manager. And I have worked as Supplies Manager for the last few years. 
- And why did you leave your previous job? 
- Well, first of all the job involved much travelling but I have small children to look after. So, my heart was breaking when I left my kids home. I used to go on business abroad and sometimes I was away from home for a few days. So, I decided to quit and now I am looking for the position of shopassistant.I find it more suitable. I won't have to leave home. Besides, I have enough experience to do the job. 
- Well, you have excellent references from your previous job and wide-ranging experience in trade. You'll start on 10000 rub. and if you do well we''ll review it after the term of probation, which amounts to 3 months. Have you got any questions for me? 
- What are the working hours? 
- The hours are from 9 till 6 p.m. with an hour for lunch. Does it suit you? 
- Yes, sure. When do you want me to start, sir? 
- In a week, if possible. 
- All right. 
- Fill in the application form and get ready to start working in a week. It was nice meeting you. Goodbye. 
- Thank you. Goodbye.

1. Sally helps her mother about the house every day. - Present Simple

 (тут просто переписываешь своё предложение, это и есть Present Progressive)

Sally has helped her mother about the house yet - Present Perfect

2. Bob makescoffee every afternoon. - Present Simple

Bob is making coffee now. -  Present Progressive

Bob has already made coffee. - Present Perfect

3. I often read the English fairy tale. - Present Simple

I am reading the English fairy tale. -  Present Progressive

(ну а тут само предложение переписываешь, это и есть Present Perfect)