French language Q&A Forum

Hi, I completed this sentence with 'n'est-ce pas' but it was marked incorrect. I'm confused. The correct answer given was 'n'est pas': I checked the attached lesson (to understand why my answer was incorrect) but I still I don't see why.

Elodie est très bonne actrice, ________ ?

My best friend Pierre, who until last year shared a 2-bedroom apartment with me in Paris,

Mon meilleur ami Pierre, qui jusqu'à l'année dernièrer partageait un appartement de deux chambrtrois-pièces avec moi à Paris

Why can't I use l'annee derniere here?? the grammar doesn't explain! 

Thanks guys... can't do accents on this page

There seems to be a subtle difference between en même temps and à la fois when expressing "at the same time"; can you state the general rule?

 I am reading "Le Petit Prince" and noticed that sometimes, passé composé is used in the description (NOT the dialogue)  instead of passé simple. In simple sentences like "J'ai ainsi vécu seul" and "J'ai vu un petit bonhomme tout à fait extraordinaire". 

There are instances where you can (or *have to*???) use passé composé in literature? I can't find any pattern so can someone explain this to me?