all of you vs you all : Both phrases usually mean the same thing, but "You all" is very informal. And sometimes (especially in the American southern states) is can be addressed to one person! You might see it in print as "Y'all." all of the crowd vs the crowd all and all the crowd. Of the three, "all the crowd" is more commonly used than "all of the crowd." "The crowd all" is incorrect. Hope this helps. they both vs both of them