you can talk —(also: you should talk) you are in no position to criticize because you are at least as guilty as smb. you are criticizing (used as an ironic or sarcastic response to a person who has just spoken):
- “Debra’s house is always such a mess!” “You can talk! Your house is even messier than hers!”
you can’t talk —(also: you shouldn’t talk) = you can talk:
- “Andy’s always late. He won’t be here in time for dinner.” “You can’t talk. You haven’t been on time for dinner for years.”