French language Q&A Forum

The full text says office DU tourisme, and my de was corrected to du.  I thought it was de and the admittedly unreliably Google translate says de ... but even the vocab list at the beginning of the lesson says de.  Merci.

I don't understand why this sentence could have is avait pu, where in no. 4 the answer is aurait pu, both meaning "could have"

In the question:  "À qui sont ces balles ? ", why is the alternative translation of "These are mine", "Celles-ci sont les miennes" wrong?

I want a lesson in using the above topics. How do I find the lesson for a specific problem AND... can I make a lesson if there isn't one already?

Thanx timothy

il en existe toutes sortes - why isn't is  this : il en existent toutes sortes.

Thanks

Paul.

Is there a way to review all my answers at the end of the exercise? To see an overall comparison of what I wrote vs what the answers are.

Should you say il est derrière la maison or il est en arrière de la maison or il est arrière la maison.

Why is my answer (deux milliards d') wrong? The lesson doesn't explain plural milliards.

Elsa has two thousand euros on her account.

Correct: mille
Incorrect: milliards d'

I'm reading https://www.lawlessfrench.com/grammar/plus/, and there's either an error or an ambiguity.  In the sections of plus used as a comparative or superlative adverb, it mentions liaising, but in the section for its use as a negative adverb, it says "In negative constructions, plus is always pronounced [ply]", with no mention of liaisons, which to me means that you should never liaise in the negative.  It gives the example of "Il n’est plus en France", which based on that rule, would mean you neither pronounce the S nor liaise it to "en".  I asked about that example on reddit, and several native French speakers said that liaising was optional, with some saying it depends whether formal or informal.  So, which is it?