The strongest response for black, if not the most common, to the English opening is 1...e5. The automatic and most common second move for white in the position is 2.Nc3. The English is such a rarely played opening that amateur players often don't quite know where to go from here. Let's look at 6 examples of responses by Black, starting with the most common.
Overwhelmingly the most popular response for Black is 2...Nf6. The common line is 3.Nf3 Nc6 4.g3 d5 5.cxd5 Nxd5 6.Bg2 Nb6 7.O-O. That's a line which, as a White player, leaves me very happy. In this game, there were a few mistakes in the opening which left White up a pawn and much happier than he deserved to be.
Another possible second move for Black is 2...Nc6. This wants to be a Reversed Sicilian. To get out of that line, I played 3.Nf3 as White to lead to a basic Three Knights System. Out of his element, Black played an obscure, goofy attack on move 3 which left things in my favor.