relative pronouns

What I know so far :
The relative pronoun used as a subject of a dependent clause is "qui", for a direct object is "que", to replace the preposition de is "dont" and for place and time is "ou".

What if it is a indirect object? For example:
Lise a envie de voir sa mere. Elle pense souvent a sa mere.
Which relative pronoun is used to replace "sa mere"?

Thank you for using the Jiskha Homework Help Forum. To answer your questions first:

Lise a envie de voir sa mère. (direct object) = Lise a envie de la voir.
Elle pense souvent à sa mère. = (with disjunctive pronoun) Elle pense souvent à elle.

More about relative pronouns. (summary)

qui = who, which, that, whom = subject (for persons and things) OR object of preposition, for persons

que (qu') = whom, which, that = object of verb (for persons and things)

lequel, laquelle, lesquels, lesquelles = which = objct of prepositions, for things

dont = of whom, of which, whose = for persons and things

où = where, in which, on which = expressions of location

ce qui = what/that which = subject

ce que (ce qu') = what/ that which = object of verb

ce don't = what/that of which = with expressions taking "de"

You may not have met all of them yet so I didn't give you anything in depth but you'll have a "preview" of what is to come!

Mme

Lise a envie de voir sa mere. Elle pense souvent a sa mere

The exercise we are suppose to do is to make it into one sentence.

Lise a envie de voir sa mere qu'elle pense souvent.

or

Lise a envie de voir sa mere qui elle pense souvent.

Which relative pronoun do you use?

Ah! Thank you for clarifying. It is important to know that you have the one sentence.

Lise a envie de voir sa mère à qui elle pense souvent = whom. (See the first "qui" on the Relative Pronoun Chart.

Perhaps this makes a better comparison for you:
Lise, qui pense souvent à sa mére, a envie de la voir. (Lisa, WHO (subject) often thinks of her mother, wants to see her.

Lise a envie de voir sa mère à qui (WHOM, object) elle pense souvent.

Please let me know if you would like more examples because it's with practice that this will become less confusing.

Mme

so in general when we want to replace an indirect object (in this case, her mother) we use a(accent) qui?

But for a direct object, we use que.
For a subject, we use qui.

Yeah, more examples would be helpful, thanks.

Qui: = who, which, that: subject of a verb; used for both persons and things.

Où est l'enfant QUI s'est fait mal? = Where is the child who hurt himself?

Le français est une langue QUI nous plaît. = French is a language that pleases us.

Que (Qu'): = whom, which, that : direct object of a verb; used for both persons and things.

C'est l'actrice QUE nous avons vue hier soir. = She is the actress (whom) we saw last night.

Voici les phrases QU'il a traduites. = Here are the sentences (that) he translated.

Qui = whom: objct of a preposition; used only for persons

Philippe est l'ami avec QUI j'étudie. = Philip is the friend with whom I study.

L'homme à QUI vous parliez est millionnaire. = The man to whom you were speaking is a millionaire.

It looks like you have the basic idea. Now, just practice! Hopefully you have a good textbook with exercises.

Mme

To replace the indirect object "sa mere" in the dependent clause, you would use the relative pronoun "à qui." The relative pronoun "à qui" is used to refer to a person who is the indirect object of the verb in the main clause. Here's how you can form the relative clause:

Lise a envie de voir sa mere, à qui elle pense souvent.

In this sentence, "sa mere" is the indirect object of the verb "pense" in the main clause. To replace it, we use "à qui" in the relative clause. So, the relative clause becomes "à qui elle pense souvent" which means "whom she often thinks of."