English Translation
You’re much faster than me.
Γρήγορη, if something, no? Or something like Πάτε γρήγορα…, no?
There are numerous options, here, and γρήγορα is only one of them. You could say, e.g., είστε πολύ πιο γρήγορες από μένα (talking to several women), είστε πολύ πιο γρήγορος από μένα (talking to one male in formal register), etc., etc. The γρήγορα might be adverbial (I’m not sure), but it could also be used in addressing, say, children - or horses. Which might sound silly, but I can see a children’s book where a donkey is talking to his horse friends . . .