French language Q&A Forum

Bonjour!

Can someone please help me to understand the difference between using qui est-ce qui vs qui est-ce que?

Qu'est-ce-que cette citation veut dire ? 

"he must be worried sick at the idea that I'm worried/anxious about his silence" ?

Quoi ? S'il a mal, avec intoxication d'alimentation, cloué au lit, il a plus des problèmes que si elle est inquiété, non ?

Si ça n'est pas correct, je n'en aucune idée. 

I’m confused by the instruction given for how to use this phrase.  Both present and imparfait are defined as “used to” in the examples.  what am I missing?  Of course for the very first question about this topic I bombed. And I don’t know why. Is there any additional instruction on this topic?

The lesson re the above clearly states that “If it/ he/ she is followed by a determinant you will use c’est.” Why then, after taking Lucie’s temperature does the doctor say,  “ Elle est un peu élevée” and when taking her blood pressure, “Elle est un peu basse”? I can understand why he would say “Elle est élevée” or “Elle est basse” but surely the given answer contradicts the rule.

une pomme à cuire = a cooking apple jumps out to me as an odd one out. You wash with a washing machine, iron with an iron and sew with a sewing machine but the apple is the one being cooked here. Is this a peculiarity of edible things or does the French just work differently to English?

I believe the English should say ‘Tomorrow Federer will lose to Roland Garros’.

I put "passé" rather than "passée" - usually a straightforward mistake - but on this occasion, I'm thinking and thinking, but I can't see what it is that "passée" is agreeing with. La soixantaine? Or Forme physique? And if so, why ?

That example doesn't make sense to me, if they are referring to the duration of time they spent in Spain, then why use an instead of année ? Even without the need of emphasizing the amount of time they spent in Spain, wouldn't the usage of année be required anyways due to the rule stating that you should use it when considering the amount of time in it's duration ?