vous vs. tu
Hello. I don't understand when you would use vous and tu. Are there certain times to use each of them? Is one more formal than the other?
In addition to previous comments, if you have any doubts always use "vous". You will not be wrong and no one will be upset. When staying with a french family whilst helping to supervise a school french exchange (I was a teacher but not of french), I was invited to "tutoyer" (use tu) after a few days of getting to know each other. We remained friends.
This is a highly complex and nuanced subject, way beyond the capacity of Duolingo, and one of the best explanations I have ever seen is this from a well known French teacher - https://www.youtube.com/watch?v=noYZ78HGmZ0.
Unless you are very experienced (or French!) I suggest you stick to Jim Horner's recommendation to use «vous » unless invited to use «tu ». (As an illustration of how complex it can be my late mother, born in pre-war St Jean de Luz, was happy for us to use «tu » to her at home but at any public gathering such as a hotel or restaurant she insisted we used «vous » - but she was spectacularly old-fashioned and formal, way beyond normal modern usage!)
"Tu" - used for one person(singular)/ used informally (e.g. friend) "Vous" - used for a group of people ("you guys")/used informally (e.g. teacher) Hope this helps!