"I am a man and you are a woman."
Translation:Je suis un homme et tu es une femme.
Both mean "you are" and are counted as correct here on Duolingo.
In real life, use "vous" with groups of people (plural you) and to address strangers, your boss, your teacher, and anyone to whom you owe respect (singular you).
Use "tu" for family, friends, and children.