1) "sois" can be the verb "to be" conjugated in the imperative mode : "Sois patient!" = Be patient! Or : the verb "to be" conjugated in the subjonctive mode (je and tu) : "Il faut que je sois patient." = I must be patient (literally: it is necessary that I be patient) "Je veux que tu sois heureux." = I want you to be happy. 2) There are too many differences to be covered in one post. They are roughly the same as in English (ex : walking/walked). Some examples with "marcher" (to walk) : participe présent : marchant - participe passé : marché. - Participe présent : ex : J'ai vu un homme marchant le long de la route. (I have seen a man walking down the road). ex : J'apprends mes leçons en marchant. (I learn my lessons, (while) walking) - Participe passé : ex : J'ai marché trois kilomètres. (I've walked 3 km). Both 'participes' can be used as adjectives. ex : coupant / coupé - Cette lame est très coupante. (This blade is very sharp) - Ce gâteau est coupé en parts égales. (This cake "is" cut into equal parts) It sounds pretty akward in English, but I hope you got the French parts!