Relative pronouns - after prepositions

1 Dont

Dont is the equivalent of of which or whose in English - it stands as a part of a relative clause introduced by de:

C'est le professeur de la fille  →  La fille dont il est le professeur ...

He's the girl's teacher. The girl whose teacher he is ...

J'ai acheté la voiture de Paul →  Paul, dont j'ai acheté la voiture, ...

I bought Paul's car. Paul, whose car I bought ...

Il vous a parlé de l'affaire →  L'affaire dont il vous a parlé ...

He spoke to you about the matter. The matter which he spoke to you about ...

Nous n'étions pas satisfaits du repas →  Le repas dont nous n'étions pas satisfaits ...

We weren't satisfied with the meal. The meal we weren't satisfied with ...

2 The structure of dont clauses

2.1 Dont first word of clause

Dont is always the first word of the relative clause . This contrasts with the English of which used to express possession, which is preceded by the thing possessed:

La société dont le nom m'échappe pour le moment ... 

The company the name of which escapes me for the moment ...

2.2 Used with le, la rather than son, sa

The nouns with which dont is used to indicate possession are always preceded by le, la or les, whilst in equivalent English clauses involving whose no article is used. English learners of French often wrongly add a possessive adjective :

La femme dont le nom m'échappe pour le moment ...

[and not * dont son nom m'échappe pour le moment] ...

The woman whose name escapes me for the moment ...

3 After prepositions except de

Where the relative pronoun stands as a part of a relative clause introduced by a preposition other than de, the rules are as follows:

3.1 [Preposition] + qui

This is used for people:

Tu parlais à l'homme  →  L'homme à qui tu parlais ...

You were talking to the man. The man you were talking to ...

3.2 [Preposition] + lequel, laquelle, lesquels or lesquelles

This is used for things:

Je me trouve dans une situation difficile  →  La situation difficile dans laquelle je me trouve ...

I find myself in a difficult situation. The difficult situation I find myself in ...

3.3 Quoi

Quoi is used after prepositions when the relative pronoun refers to a fact or idea rather than to a person or thing:

Je lui ai dit que je n'aimais pas Mozart, à quoi il a répondu que ...

I told him that I didn't like Mozart, to which he replied that ...