For example, When I want to say:
I have joined a company X.
J'ai rejoint une entreprise X.
Why we are using the "rejoindre" verb not "joindre", here? When to use each of these verbs
Joindre means to connect two entities, to make them touch/communicate/act together.
Joindre les deux bouts. To make end meet.
Joindre l'utile à l'agréable. To mix business with pleasure.
Rejoindre means either to reconnect things that were disconnected before or to move toward and reach someone/something.
The meaning is sometimes equivalent:
Venez nous rejoindre ! Come and join us!
Venez vous joindre à nous ! Come and join us!
but sometimes, it is clearly different. Compare:
Je n'ai pas réussi à le joindre : I was unable to reach him (because he didn't pick up the phone).
Je n'ai pas réussi à le rejoindre : I was unable to reach him (because I was too slow).
