Why in English "join with us" incorret, but the right is "join us" can you explain it?

Question

Answer

Raja is correct.

Join us = Come and enjoy our company.
Join with us = Come and be like us

Answer

It depends on the sentence. They are both used. They have the same meaning, essentially. What is your sentence?

JOIN WITH US is "grander" as in:
"JOIN WITH US IN THE STRUGGLE!". (strike, revolution, petition)
vs. 
JOIN US FOR DINNER!  or Why don't you JOIN US FOR A MOVIE?

Answer

It depends on the sentence. They are both used. They have the same meaning, essentially. What is your sentence?......

JOIN WITH US is "grander" as in "JOIN WITH US IN THE STRUGGLE!". vs. JOIN US FOR DINNER!