Написать хвостиковый вопрос we had a longer stop in pskov three hour ago. our bus is ahead of schedule fred always pays cash the train is due to arrive in berlin at 6.00

We had a longer stop in Pskov three hour ago, didn't we?
Our bus is ahead of schedule, isn't it?
Fred always pays cash, doesn't he?
The train is due to arrive in Berlin at 6.00, isn't it?