French language Q&A Forum

I've encountered this quiz: translate this sentence: "Marie worked for ten hours yesterday". The answer excludes this option: Marie a travaillé en dix heures hier.

Why can't I use the word "en"? It's mentioned here: En vs Dans with time (French Prepositions of Time)

"En expresses the length of time something takes to be done."

I know that she did not say Tu vas l'adorer but why didn't she?  Is it an idiosyncratic expression that doesn't require an object?

The singular to  Ces garcons parlent francais

This was a great exercise. Just wanted to flag that sometimes after submitting responses, no corrections displayed and I was therefore unable to mark myself.

Hello,

Would you kindly explain the "en ferait rougir plus d'un"? I am not sure what the speaker is saying about Damien. Is she implying that Damien has a way on making someone blush (with embarrassment perhaps)? 

Merci!

Not complaining, but I wonder if you could explain why sometimes the "your answer matched mine" differs from the version in the text on the final page? For example I had "nous apprenons de nouvelles choses chaque fois que nous le faisons !" marked correct but it becomes "à chaque fois" in the full text at the end. And several times my answer is red-pencilled but then is given as a possible alternative. Does this reflect later editing of an exercise or mean maybe that my answer was ok but not the best?

Hello,

I was wondering, for this question:

why the answer is vieil and not vieux, like from the list on adjectives that go before nouns?

If would have + movement verb uses Être, would this apply to should have and could have versions of the same sentence? Or do they continue to use avoir + dû/pu ?