2. greengrocer / greengrocers/ sell fruit and vegetables 3. postman / post office / take letters to peoples houses 4. waiter / cafe / serve people

1 A teacher works at a school. She teaches students.
2 A greengrocer works at a greengrocer’s. He sells fruit and vegetables.
3 A postman works at a post office. He takes letters to people’s houses.
4 A waiter works at a café. He serves people.