French language Q&A Forum

So when does one use mille and milliers de?  Are they interchangeable?

Why is "Nous avons seulement deux chambres" incorrect?

I understand why "Nous n'avons que deux chambres" is correct, but if I understood the lesson correctly then the option with seulement should simply be informal, but correct just the same.

My answer is milliers d'
but somehow its not correct. It should be mille.

deux mille euros
deux milliers d'euros

both are correct, right? How come my answer is right?

I'm struggling to see the use of "l" in the phrase : mais je pense que l'on mériterait