"Qui" refers to a person and generally means "who" or "whom." Depending on where it is in a sentence or question, it can be either the subject or the object of the sentence.
"Que" refers to a thing and generally means "what." It can also be the subject or the object of the sentence depending on it's placement.
I like to think of the 5 Ws in English as the 5 Qs in French (although they're not all Qs).<pre>
Who/Whom -- Qui What -- Que/Quoi (*) When -- Quand Where -- Où Why -- Pourquoi</pre>
(*)From what I've heard/seen, "quoi" is frequently used as a stand alone sentence, but not always. Say someone is informing you that your car was stolen, you would say "Quoi?!" or "What?!" possibly followed by expletives. "Que" is frequently used in questions (see the second link) but can be used in normal sentences too.
Ooo, your question is keeping me on my toes. Thanks for kicking me into gear and getting me to research my own weakness. :)
While they both mean "what," que and quoi cannot be used interchangeably.
According to link B, if you follow "normal word order" or if "what" follows a preposition (aka, is the object of the preposition) you would use quoi. "Normal word order" is also called "in situ" and is probably something I should research more before being a voice of authority. I'm guessing my previous example of exclaiming "What/Quoi?!" after hearing your car is stolen probably falls under this "in situ" concept as it is likely short for something like "What are you talking about? What are you telling me? What just happened?". Link A briefly talks about using quoi after a preposition, but doesn't really explain why. To explain the preposition part a little more, if you have a complete sentence, but want to add more information about the verb or the noun, generally you'd add a prepositional phrase like "You are going to pay…with what?" The "with what" part is not necessary to have a complete sentence, but does add more information to the verb "pay." This sentence in French would therefore be "Vous allez payer…avec quoi?"
If the "what" has something to do with a verb (as opposed to a noun) and is not part of a prepositional phrase, you should probably use que. According to link B, if "what" is the object of the verb (as in, the verb is doing something to the "what"), you can form a question using "qu'est-ce que…" or inversion, but if "what" is the subject of the verb (aka, the "what" is doing the verb), you must use the "qu'est-ce qui…" form followed by the third-person (il/elle/on) conjugation of the verb. If "what" is the subject of the verb, inversion is not correct. (Link A is the one that mentioned the third-person conjugation.) For example, if something happens and you are inquiring as to what did the happening (you hear a boom and what to know what made it) then "what" is the subject (because it did the something) and you would use "qu'est-ce qui…". However, if you already know what the noun doing the something is and want to know more about that noun doing the something, than your "what" is the object of that verb and you'd use "qu'est-ce que…" or inversion.
Link B also goes into non-question sentences using "what," but I will leave that to you to read as this is getting complex enough and isn't used quite as often.
I know I may have gone overboard with the explanation, but doing so helps me learn it and ingrain this new knowledge for myself. Thanks for getting me to learn!
Agreed. I'm still shaky on parts these things, but the more I hear the proper phrases in the proper contexts, the less I have to think about which words I'm using where and the correct phrases just flow out of my mouth. I highly recommend augmenting your Duo learning with some French podcasts, movies, books, etc.
I think that "par" translates as "per" in the sense of "for each." As in, 90 km per hour, $10 per person, that sort of thing. "According to" would be salon, suivant, or d'apres. There are dozens more meanings of the French "par" than the English "per," but I don't think "according to" is one of them.