I'm not sure how you define "english," but the standard definition is: "sidespin." Yes, when you hit the CB off center, even a small amount, the CB will have sidespin off the tip. Now, as the CB travels down the table, the sidespin is lost gradually (with the rate depending on shot speed and cloth conditions). Also, when the CB hits an OB at an angle, the CB will pick up a small amount of outside spin (based on how much the OB throws) or have any inside spin reduced (or converted to outside if the amount of inside spin is small enough). Therefore, whether or not a CB has sidespin when it hits a rail depends on how much spin there is to begin with, the spin's direction compared to the cut, the speed of the shot, the distance traveled before hitting a rail, and cloth conditions.
But again, "english" is "sidespin," and hitting the CB off center (even a small amount or "touch") creates sidespin (AKA "english").
Now, to get a reaction off a cushion (i.e., a change in rebound angle), the CB must have sidespin when it reaches the cushion.
Best Regards,
Dave