Bonjour !
Voici la réponse :
I have seen this movie before. ⇒ I saw this movie a few weeks ago.
Oh ! I’ve lost my wallet ! ⇒ I lost my wallet yesterday.
I have been through many troubles in my life. ⇒ I was through many troubles in my life especially on Tuesday.
I've just met him on the street. ⇒ I met him on the street a few hours ago.
I haven't done it yet. ⇒ I didn't it yet. EXCEPTION
We have never done such a hard test before. ⇒ We never did such a hard test before.
J'espère que je t'ai aidé ! :)
Bonne journée
Nolan
;-)