What is the rule as to when Qu'est-ce qui is used rather than Que?

Question

I have read through the lesson twice. There are many examples given but no clear guidance as to what they are supposed to be illustrating? Please could someone clarify? Thanks very much, David

Cécile Janty-Davies · Accepted Answer

Hi David,
If what you are asking is the difference between: Qu'est-ce-qui? and Qu'est-ce que? both meaning 'What?', then it is a question of grammar. 'What' being the subject or the object in the sentence. Have a look at the following examples:
Qu'est-ce-qui est arrivé? ( What happened?), in this sentence 'What' is the subject of the verb to happen.
Quest-ce-que tu veux? ( What do you want?), in this sentence 'What' is the object of the verb to want.
Hope this helps!

Ron Thomas · Answer

Bonjour David,
Qu'est-ce que and que are pretty much synonymous ---> what. Qu'est-ce qui, when using this phrase, it will ALWAYS be followed by a verb whereas qu'est-ce que will be followed USUALLY by a noun or other subject in the same manner as que tu est triste instead qui est triste.
Here are a couple of links that might help:
https://www.lawlessfrench.com/grammar/interrogative-pronouns/ (this one is written by Laura from this site)
https://www.laits.utexas.edu/tex/gr/int5.html
Hopefully these additional resources can help clarify this for you.

Bonne chance et bonne continuation !

Chris Wirt · Answer

You use "Qu'est-ce qui..." if "qui" is the subject of the following sentence. And you use "qu'est-ce que..." if "que" is the direct object of the sentence. For example:

Qu'est-ce que tu as fait? -- What is it that you did? (literal translation)
Here "you" is the subject of the clause and "que" (=that) is the direct object. Hence: que.

Qu'est-ce qui fait le bruit? -- What is it that makes this noise?
"Qui" is the subject of the clause (... THAT makes the noise), hence "qui" and not "que".

Did that help any?

-- Chris (not a native speaker).

Ron Thomas · Answer

Bonsoir,
While I fully understand the response given by Chris, I still have a relevant question. 
After re-reading this question that was posed, I have the sense that possibly we both missed the intent of the question.  My take-away is this:
In what scenario would one choose to use «qu'est-ce qui» instead of just «que» and vice versa.  Also in the same manner when would one use «qui est-ce qui» instead of just «qui»?
Most things concerning the French language have definite guidelines when one form is preferred  over another, is there a similar guideline for these examples?  I have re-read the lesson and cannot find a discernible explanation.

Merci en avance,
Ron

Christophe cheung · Answer

Hello Chris , brilliant French by the way , impressive ! One comment though , I find confusing to put "qu'est ce qui"  and " qu'est ce que ", because your direct object(question word)  in the latter is not "que " per se but "qu' "! Actually the "que" you allude to is just a part of the formula to ask a standard question in French (est-ce que), hence my confusion.