3. The relative pronouns which and whom can function as the object of a preposition, as the examples set below: However this use sounds rather formal, and it is much more common to place the preposition towards the end of the clause rather than before the relative pronoun, as in e.g.: the room which we are staying in an achievement which I am very proud of the man who she has an affair with the report which he is referring to the room in which we are staying an achievement of which I am very proud the man with whom she has an affair the report to which he is referring
4. and very often the relative pronoun is left out altogether, as in e.g.: Note that if the verb in the relative clause is a phrasal verb which ends with a preposition, this preposition can never be placed in front of the relative pronouns which or whom, e.g.: the room we are staying in an achievement I am very proud of the man she has an affair with the report he is referring to * This is just the key issue with which I have to put up. This is just the key issue which I have to put up with . * wrong.
5. If the relative pronoun is functioning as the indirect object of the verb in the relative clause, the prepositions to or for are used, e.g.: the girl ( who/that )I lent my jacket to the person ( who/that ) I poured a drink for
