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

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.thoughtco.com/qui-vs-que-1368925 (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 !

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).

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

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!