There are many options for black.I think in terms of 3 basic categories. 1) c4,e5 which is a reverse Sicilian. 2) c4,d5 d pawn defenses. And 3) c4,c5 the symmetrical English. Which can transpose into a Benoni if white chooses to play d4 as well.
Which is the best defense against english opening?

There are many options for black.I think in terms of 3 basic categories. 1) c4,e5 which is a reverse Sicilian. 2) c4,d5 d pawn defenses. And 3) c4,c5 the symmetrical English. Which can transpose into a Benoni if white chooses to play d4 as well.
1.c4 d5 is bad for Black.
A lot depends on what Black plays vs d4. Here are the legit responses to 1.c4:
1...e5
1...c5
1...Nf6 2.Nc3 and now:
2...g6 can be played by King's Indian players
2...d5 by Grunfeld players (2...g6 3.e4! And only then 4.d4), but you have to know anti-Grunfeld lines.
2...e6 by Nimzo players, but you need to know the Anti-Nimzo (3.Nf3) and Mikenas-Flohr (3.e4)
1...b6 - English Defense
1...f5 - Dutch player can play this
1...g6 - Modern Defense
1...c6 or 1...e6 followed by 2...d5 transposing to the Closed Reti or the Reti-Slav unless White transpose to a queen pawn opening.

Yes, you are correct. That was what I was trying to explain in simple terms. He is a 800 player and I didn't want to bombard him with reams of information.

I usually play queen's indian, or grunfeld
Then probably 1...Nf6 followed by 2...g6 and you'll probably get a Grunfeld-like position if not a direct transposition.

Kings English is really great... there's surprisingly little breadth to the theory, not sure why because it's a reversed sicilian but white just always plays the same moves. Of course whatever you play depends alot on the rest of your repertoire but if you're a sicilian player definitely look into the kings english.
I usually play queen's indian, or grunfeld