1 - rencontrer = meet I meet Anne = Je rencontre Anne. We use " rencontrer " when meet someone. 2 - retrouver = find for second time I found my keys = J'ai retrouvé ( or " trouvé " ) mes clés. Note: we can say " retrouver " in the place of " rencontrer " but when we meet someone the most word that is " rencontrer ".

The correction of Lokmane is true, I will try to complet it. Rencontrer = To meet for the first time Trouver = To find and Retrouver = To find again We use "retrouver" in different cases : 1- J'ai retrouvé mes clés = I found my keys. 2- "Je retrouve mes amis à 9h" means you have a meeting at 9 with tour friends. I think in english you say "I meet my friends at 9 o'clock" or "I see my friends at 9 o'clock". 3- You can say : "J'ai retrouvé mon veil ami" which means you meet your old friend who you didn't see since ages. I don't' know if you can say in english "I found my old friend". I hope I was clear, I'm sorry for my bad english!