hi , i would like to purchase a train ticket .
user
i can help you with that . where would you like to arrive and depart from and on what day ?
assistant
i want to depart from london liverpool street on saturday leaving after 08:30 to go to cambridge
user
tr0357 will leave at 09:39 , would that work for you ?
assistant
that sounds like it will work . can you book 7 seats for us ? i'll need a reference number .