"English," or sidespin, is a powerful tool in billiards that allows players to precisely manipulate the cue ball's path, particularly after it contacts a rail or another ball. By striking the cue ball to the left or right of its vertical center, you impart a rotational spin that significantly alters how the cue ball rebounds off cushions, enabling it to take wider or narrower angles than it would with a center-ball hit. This strategic application of spin is vital for advanced position play, allowing you to guide the cue ball to specific areas of the table for your next shot, navigate around obstructing balls, or even influence the "throw" (deflection) of the object ball on a cut shot. While it offers immense control and expands your shot options, using English effectively requires understanding and compensating for effects like squirt (the cue ball deflecting slightly opposite the direction of spin from your cue tip) and swerve (the cue ball curving across the cloth before reaching the object ball), making it a nuanced skill that demands considerable practice to master.