French language Q&A Forum

I conjugated Elles font and was told that Elles fait is correct. I don't think think that is true. Could you please examine that question and explain the answer to me?

"Jacques est descendu du haricot magique." was translated to: "Jack got off the magic beanstalk." I answered, "Jack climbed down the beanstalk" and it was marked wrong. Larousse clearly states that "descendre de" (using etre as the auxiliary verb) means "climb or climb down". Hence, my confusion.

idioms  confound me ... "on the edge" of town is different than of a cliff ... what is the idiom for "on the edge of my seat" or almost being driven crazy  as saying "he's really on edge" ? maybe an "edgy" lesson?

In the article we mentioned answering simple questions with "ni l'un ni l'autre" like: 

Quel parfum tu veux ? Fraise ou vanille? - Ni l'un ni l'autre. 

The "ni l'un ni l'autre" is used to replace "parfum", which is the object of the verb. Are there any instances where ni l'un ni l'autre can be used as a direct object or an indirect object in a full sentence? Thanks!

Is it 'des' because the reference is to some brown hair? I thought it always had to be:  les cheveux !

Also, DES lèvres fines ,  but DE dents blanches! Cecile's response below indicates that "de" = of,  while the 'des' related to thin lips means some?  Would really appreciate clarification.

I never know what to do when I've been writing informally and suddenly find that I have to use first person plural pronouns other than the subject pronoun.  How would you say something like "We fed our pets" or "They will find us if we stay here" in casual French?

"marcher a l'ecole" translates to "walks/is walking to school" so why was this marked wrong?

I have noted in another post recently that it is a frustration, annoyance even, to come to a lesson, struggle with a concept, and then find the same question arising often in Q and A. The Q&A section is often very long, and repetitive with a mix of highly relevant and less relevant comments (like this one in this section perhaps? - shrug), and reading all the way through it after every section, is not the most efficient use of study time. I suggest that when the urge arises to write in response to a question anything along the lines of 'this has been asked and answered before', that should signal the need for the question/answer to be directly addressed in the lesson - initially an addendum tagged in at the end of the lesson, but subsequently properly incorporated, for example. This is presented as an opportunity for improvement rather than just a criticism - as the end product will be much better lessons. Others may have other suggestions to address this and improve further.