Ответ:

This cup of coffee is cold, isn't it?

Sarah's sister wasn't tall, was she?

Thomas didn't give me the money, did he?

Diana taught me English, didn't she?

The plane wasn't on time, was it?

The Maths exam is easy, isn't it?

Katherine comes from USA, doesn't she?

The shepherd's dog is big, isn't it?

A farmer grows vegetables, doesn't he?

Sylvia hated carrots, didn't she?

They couldn't sing a song, could they?