He can read a book, can´t he?
It takes about 2 hours by bus, doesn´t it?
They were at the office, weren´t they?
If the sentence is negative, the tag question is affirmative.
The bus doesn´t arrive at 4:00, does it?
Layla didn´t buy her dresses, did she?
The man hasn´t come yet, has he?
Tag questions are usually added to confirm information. Pay attention to the tenses used. They have to be in agreement with the tag question used.