8.98 formal use

In formal English, the preposition can go at the beginning of a clause in front of 'whom' or 'which'.

• These are the people to whom Catherine was referring.
• ...a woman friend with whom Rose used to go for walks.
• ...questions to which there were no answers.

Note however that you cannot put the preposition at the beginning of a clause in front of 'who' or 'that'.