French language Q&A Forum

Why dont we say that "J'ai entendu tout" like "Je comprends tout" but "J'ai tout entendu"?

My question is about a quiz question in this unit: "J'ai décidé d'apprendre à jouer du piano cette année." How do you know it's "apprendre *à* jouer" instead of "apprendre *de* jouer," for example. I think that French verbs differ in this respect, but I haven't seen any systematic explanation of it, and I don't even know how to talk about it in a way that could make internet search productive. Do you have any teaching materials about this, or can you help me to understand it better? Thanks in advance.

The quiz question was Lucas a monté la nouvelle armoire de sa sœur

How is this different from Lucas a monté les escaliers?

In otherwords, why is "Lucas climbed on top of his sister's new wardrobe" incorrect?

Thank you

In this example of passive voice for se faire gronder why does faite end in e? I thought fait was invariable when a past participle following a feminine/ plural direct object with avoir or following être as in this case. 

"Descendre de" rule

This may have a simple answer, but if 'de' becomes du or des when followed by le or les, why would the correct response on the quiz be: Elle descend de l'avion rather than Elle descend du l'avion?

A hint in the first question suggests "use vous form" in "votre (oeuvre d'art favorite)". But later, speaking to the same person comes the response "Je suis d'accord avec toi". Is there a reason for what appears to me to be an inconsistency? Same two people speaking.

"Un vraiment beau monument" is wrong, should read "un monument vraiment beau", yet I am led to believe that using a different subject "un très beau fille" is acceptable. If my example is correct can someone please explain. Thanks/Merci

Did a quiz, apparently answered wrong, and am now very confused.

The question: Elle ________ monté le poney de Jérémie et il a été très docile.

I went with "a monté". The quiz says the correct is "est monté".

Going by the Q&A, it seems like my answer was correct.  I am stumped in two ways. 

First, the Q&A says that avoir followed by the past participle is used for getting on a horse. This is a (pro)noun followed by a direct object. The lesson uses the example a "a monté mon cheval". I'm struggling to see why the verb auxiliary would switch based on who owns the horse. 
Second, assuming I have the first part wrong someone how and être is the correct auxiliary, should the correct answer not be "est montée"? The subject is feminine.