French language Q&A Forum

I have two separate questions regarding the same example 

The first is…why do you use “sa tête” to mean “his face”? 

The second is…I am sure that there are many colloquial ways or common ways to express “should have” using the verb avoir in its conditional conjugated form when it’s not followed by “dû”, but is it actually proper French grammar? For instance, in one of the above examples, it reads: “Tu aurais vu sa tête quand je suis apparu devant lui.”  Its translation is “You should have seen his face when I appeared in front of him.” Possibly contextually it translates better to should than would. Perhaps if the sentence was “ Tu aurais vu sa tête, si tu avais été là.” Then it’s a true conditional statement-You would have seen his face (condition) if you had been there. So perhaps I’ve answered my question because this really isn’t a conditional statement However, I like rules, I like things to follow those rules (The Container Store is one my happy place-quote from Emily in Paris). I also realize that as I write this, the English language is known for not always following grammatical rules in one sense or another (although I can’t think of any because it makes sense to me as a native English speaker, so please forgive my hypocrisy). Please help me understand when avoir in its conditional form means should when not followed by dû.

Do they both mean the same thing? And if so, why does one of them change depending on whether you are a man or a woman, and one of them doesn't? 

Oh, ça ? Non, c'était la ________ !

Oh, that? No, that was last time!

My Answer - dernière fois

Correct Answer - fois dernière

If "la dernière fois" and "la fois dernière" can be used interchangably (with "la dernière fois being more restrictive") why is my answer wrong ? I don't see any relative clause here as mentioned in the lesson.

I used "les rosiers les plus beaux de" and got marked wrong—is there a reason that construction can't be used (here)?

It would be great if there were exercises after the reading section, which could be linked to the specific grammar topics (brainmap arrondissement) that a student could have gotten wrong. 

the grade yourself is rediculous. Waste of time. The exersize itself would be useful if I didn't have to click like 4 times on stuff every five words.

Asked to translate,” My father would hide in our basement…..” , we were given the hint to use devoir. Yet the correct answer given was, “ Mon père se cachait dans notre cave….”. I see no use of devoir!

Why wouldn’t you use “ ils balaieront/balayeront le sol avant nous venions “  in lieu of “avant nous ne venions “ ? I’m confused about the “ne” negation. What’s its purpose?

Can the word taux be used instead of tarif? Is there a difference between the two?

why are we using des with six ( chacun des six chateaux)  as six is the defined number