I know vous is used for plural but also for being polite. I also know that the adjective should agree with the subject. So, if I'm saying to two or more people that they're sympathetic, then I would ...
When talking to someone, how do you decide when to use "vous" or "tu"? Example: Comment allez-vous ? or Comment vas-tu ? Comment choisir entre vous et tu quand on s'adresse à ...