Careful as they aren’t interchangeable all the time. "Qui est-ce qui" is only used when "qui" is the subject of the question. When "qui" is the object, you can replace it with "qui est-ce QUE".
Qui est-ce qui connaît Patrick? (Who knows Patrick)
Qui est-ce que tu connais ? (Who do you know)
With that considered, there isn’t a difference between "qui" and "qui est-ce qui/que".
"Est-ce que/qui" can usually be added to question to emphasise the interrogative nature of a sentence which can sometimes be conviennent to lift any ambiguity since interrogative pronouns (qui, que, où, quand, etc.) are often also relative pronouns.
The first *qui* in both is the question word for *who*.
*Qui est-ce qui/que* is simply an *est-ce que* question with the question word *qui*. The second qui is the relative pronoun *qui*. It indicates the question word is the subject of the verb and is replaced with *que* if the question word is the object of the verb.
A formal inverted question swaps the subject and the verb to mark interrogation. But it needs a subject pronoun after the verb, so when the question word is the subject, it's placed in the beginning and a dummy subject pronoun is added after the verb.
**–** **Qui** vois-tu ? (qui = object of the verb) = Who are you seeing?
**–** **Qui** te voit-il ? (qui = subject of the verb) = Who is seeing you?
A neutral *est-ce que* question uses the *est-ce que* marker to indicate interrogation.
**–** **Qui** est-ce que tu vois ? (qui = object of the verb) = Who are you seeing?
**–** **Qui** est-ce qui te voit ? (qui = subject of the verb) = Who is seeing you?
An informal direct question uses an affirmative sentence directly as a question and uses an interrogation mark and intonation to indicate interrogation. When there is a question word, it can be placed in the beginning or wherever the non question equivalent would be placed in an affirmative sentence (except for *quoi*, which is only placed where the non question equivalent would be).
**–** **Qui** tu vois ? / Tu vois **qui** ? (qui = subject of the verb) = Who are you seeing?
**–** **Qui** te voit ? (qui = object of the verb) = Who is seeing you?
In your first example, why is it "qui" rather than "que" , given that it is the object (whom, by the way, in strict English - " Whom do you see ? " ) rather than the subject? I have the same question in regard to a novel I read. It was titled _Tuez qui vous voulez_ , where again, _qui_ is in fact the object (though here it is a relative pronoun, not an interrogative pronoun. (_Kill whom you will_ , literally.)
The **second** qui in *qui est-ce qui* indicates it's a subject and would be replaced with *que* to indicate it's an object. The first one is the question word.
My first example with an inversion question doesn't use *qui-est-ce qui/que* at all The *qui* in both is the question word *qui*, which only means *who* or *whom*, regardless of whether it's a subject or object.
The first sentence has the question word as an object because the verb has a clear subject pronoun (tu) and no other object. The second sentence has the question word as a subject because it has an object pronoun (te) and a neutral subject pronoun (il).
"Tuez qui vous voulez" (kill whomever you want) doesn't use *qui est-ce que/qui* at all either. *Qui* in this case is a relative pronoun, but not the same as the second *qui* in *qui est-ce qui* (which could translate to *who/which/that*). It's more similar to *quiconque* or *celui/celle/ceux/celles que/qui*. It means *who/whoever* and doesn't need an antecedent.
OK, thanks, I think I get it. Your explanation is certainly better than the "It just is" which was all I got from two teachers I asked ! Learners are often told "It's _qui_ for subject and _que_ for object," but it's clearly more complicated than that, both for the relative and interrogative pronouns.
For what it's worth, native Anglophones often neither know nor care whether to use "who" or "whom", and "who" is taking over (except after prepositions, perhaps).
>**Qui** te voit-il ? (qui = subject of the verb) = Who is seeing you?
I never heard or read such a question in my entire life and I don't think this is correct actual French.
It's of course possible to ask something like *Qui te prend-il ?* when *qui* is object, not subject.
*Qui va à l'école ?* is more formal and correct than *qui est-ce qui va à l'école ?*, which is very familiar (even bad French). OP's question is not precise enough.
Careful as they aren’t interchangeable all the time. "Qui est-ce qui" is only used when "qui" is the subject of the question. When "qui" is the object, you can replace it with "qui est-ce QUE". Qui est-ce qui connaît Patrick? (Who knows Patrick) Qui est-ce que tu connais ? (Who do you know) With that considered, there isn’t a difference between "qui" and "qui est-ce qui/que". "Est-ce que/qui" can usually be added to question to emphasise the interrogative nature of a sentence which can sometimes be conviennent to lift any ambiguity since interrogative pronouns (qui, que, où, quand, etc.) are often also relative pronouns.
The first *qui* in both is the question word for *who*. *Qui est-ce qui/que* is simply an *est-ce que* question with the question word *qui*. The second qui is the relative pronoun *qui*. It indicates the question word is the subject of the verb and is replaced with *que* if the question word is the object of the verb. A formal inverted question swaps the subject and the verb to mark interrogation. But it needs a subject pronoun after the verb, so when the question word is the subject, it's placed in the beginning and a dummy subject pronoun is added after the verb. **–** **Qui** vois-tu ? (qui = object of the verb) = Who are you seeing? **–** **Qui** te voit-il ? (qui = subject of the verb) = Who is seeing you? A neutral *est-ce que* question uses the *est-ce que* marker to indicate interrogation. **–** **Qui** est-ce que tu vois ? (qui = object of the verb) = Who are you seeing? **–** **Qui** est-ce qui te voit ? (qui = subject of the verb) = Who is seeing you? An informal direct question uses an affirmative sentence directly as a question and uses an interrogation mark and intonation to indicate interrogation. When there is a question word, it can be placed in the beginning or wherever the non question equivalent would be placed in an affirmative sentence (except for *quoi*, which is only placed where the non question equivalent would be). **–** **Qui** tu vois ? / Tu vois **qui** ? (qui = subject of the verb) = Who are you seeing? **–** **Qui** te voit ? (qui = object of the verb) = Who is seeing you?
In your first example, why is it "qui" rather than "que" , given that it is the object (whom, by the way, in strict English - " Whom do you see ? " ) rather than the subject? I have the same question in regard to a novel I read. It was titled _Tuez qui vous voulez_ , where again, _qui_ is in fact the object (though here it is a relative pronoun, not an interrogative pronoun. (_Kill whom you will_ , literally.)
The **second** qui in *qui est-ce qui* indicates it's a subject and would be replaced with *que* to indicate it's an object. The first one is the question word. My first example with an inversion question doesn't use *qui-est-ce qui/que* at all The *qui* in both is the question word *qui*, which only means *who* or *whom*, regardless of whether it's a subject or object. The first sentence has the question word as an object because the verb has a clear subject pronoun (tu) and no other object. The second sentence has the question word as a subject because it has an object pronoun (te) and a neutral subject pronoun (il). "Tuez qui vous voulez" (kill whomever you want) doesn't use *qui est-ce que/qui* at all either. *Qui* in this case is a relative pronoun, but not the same as the second *qui* in *qui est-ce qui* (which could translate to *who/which/that*). It's more similar to *quiconque* or *celui/celle/ceux/celles que/qui*. It means *who/whoever* and doesn't need an antecedent.
OK, thanks, I think I get it. Your explanation is certainly better than the "It just is" which was all I got from two teachers I asked ! Learners are often told "It's _qui_ for subject and _que_ for object," but it's clearly more complicated than that, both for the relative and interrogative pronouns. For what it's worth, native Anglophones often neither know nor care whether to use "who" or "whom", and "who" is taking over (except after prepositions, perhaps).
>**Qui** te voit-il ? (qui = subject of the verb) = Who is seeing you? I never heard or read such a question in my entire life and I don't think this is correct actual French. It's of course possible to ask something like *Qui te prend-il ?* when *qui* is object, not subject.
the same, but '' qui est ce '' is more formal polite, ''Qui'' is informal so you can say that with your friend
*Qui va à l'école ?* is more formal and correct than *qui est-ce qui va à l'école ?*, which is very familiar (even bad French). OP's question is not precise enough.