French language Q&A Forum

I was doing the exercise (https://progress.lawlessfrench.com/my-languages/french/exercises/judge/1833/14548249?response=4150265&page=7) to answer a question and now have one of my own:

There's the phrase: visiter les ruines du vieux château.

How come the rule that the definite article is omitted if there's an adjective intervening between de and the noun is not applicable here? I would have thought this should be ...de vieux château.

Could anyone please tell me if there are any rules on if and when you can/cannot replace inanimate nouns with subject pronouns? I read the lesson c'est versus il est/elle est and thought you use c'est with nouns while il/elle est is used with adjectives. 

But I have encountered situations where the writer/speaker uses il/elle est with a noun.

For example, if you are referring to (or pointing at) "une lettre", can you say "Elle est une lettre"? Or can you only say "C'est une lettre."?

Or, if you are referring to "une conversation", can you say "Elle va bien" or can you only say "Ça va bien."? 

Thank you for any clarification. 

In the statement "mon fils a de grandes oreilles" , why is it not "DES grandes oreilles"? Ears is plural, and "de" is the article, and "grand" is following a feminine plural suit.... I've noticed this with other items, mostly body parts, like toes, fingers, eyes. They all use a plural article "les" but when describing them, it turns to "de"

If I said "he had cats" it would be "il a des chats", right? What am I not getting!?

In this sentence where is the "you" as the sentence in English was "or we could give you a refund"? why are these English words just being omitted and how are we meant to know when to omit them?

J'ai choisi abimer au lieu de ruiner, un mot qui n'était pas dans mon vocabulaire avant.  C'était un mauvaise utilisation d'abimer ?  Dans la même phrase, j'ai utilisé jolie au lieu de belle.  Un autre mauvais choix?

Is there a rule about using hyphens with 'et un' when added to thirty, etc.?

This article says that the translation for "Il viendra de peur que tu ne sois vexée." is "He comes...", but wouldn't "viendra" translate to "will come"? And then "Il va venir" would be the one that is translated to "He's coming..."

I think Il a économisé en secret should have been accepted

This excerise, says 'soudain' instead of 'soudainment'... can someone speak to this for me please :) Or point me to a lesson! Thank you.

And sudden -- instead of And suddenly.