The English Opening is played the move c4.(In descriptive notation, it`s P-QB4)
The English opening is a flank opening like the Zukertort Opening(Nf3 or in the other notation: N-KB3). The origin of the English opening came from the Staunton-Saint Amant game.
What are common responses to c4? Here they are:
Nf6(Black is expecting d4 for the Indian Game:Normal Variation)
e5(English opening:King`s english variation)
e6(this may lead to the QGD-Queen`s Gambit Declined and Tarrasch Defense.
c5- The symmetrical variation
f5- leads to Dutch Defense after 2.d4
g6- may lead to Modern Def.,or after d6 and Nf6 to the KID(King`s Indian Defense or stay within English lines.
c6- can lead to the Slav Def. after d4,d5 but White prefers the Caro-Kann after e4,d5 or a Reti opening after Nf3,d5,b3
b6- english defense
g5- an eccentric response known as Myers` def.
I have been seeing d5 after c4 so I`ll add it.
d5- English opening:Anglo-Scandinavian Def.
According to wikipedia, it says that the english opening can transpose to other openings.
Famous chess players who employed it are the Latvian Mikhail Tal,
Bobby Fischer, Anatoly Karpov
and Tigran Petrosian
Thx for viewing!(Sorry for all those items all around)