Repeat the sentences after me:

He is a doctor.  He works in a hospital.

She is a waitress.  She works in a bar.

They are shop assistants.  They work in a supermarket.

I am a computer engineer.  I work for a big company.

He is an electrician.   He works in peoples houses.

You are a teacher.  You work in a school.

We are bus drivers.  We work in the city centre.