People say "It depends" when they don't know what the favour is. If they say yes, and then you say "Pay off my car loan," they probably will regret saying yes.
We can say, "I am looking for a favor from you." But if we're looking for a favor from someone, we don't usually tell them we are. We usually ask them for a favor, and leave it up to them whether or not they will favor us. After all it is a favor, not an obligation.
say that your taken.
well it depends if you like him or if you don't if you do then you should go out but if you don't just say "I'm sorry i don't thing it will work out"
If you are being respectful, say, "Cierra la ventana, por favor." If it's a friend or someone close to you, say, "Cierras la ventana, por favor."
You can only say something if its for you or someone who asked you about so I can't really say anying
Say no, but don't be mean about it.
It means, "[All of you] Say it again, please."
it depends on the person
This can be unanswered by no one replying, or say if you asked someone question and they did not reply it would be unanswered because they have not replied to the question you asked them.
The noun 'favor' is not a collective noun for any group of things. However, I have often heard people say that they had done 'a lot of favors' for someone.
It depends on the " someone else ". That person's opinion could be worthless or extremely valuable, if he/she is very knowledgeable about the topic. In general, we say that opinions are cheap ( usually freely given even if not asked for ) but actions are priceless.
Personally what I think you should say is " Thank you that was very kind of you" but if you can return a favor I think you can say " Thank you I will repay you someday"