In running that list against B::Keywords (an extract of perl's recognized barewords) I come up with the following forty intersections: and, close, connect, continue, die, do, each, else, for, if, join, kill, last, length, listen, log, map, my, next, no, open, or, our, print, push, read, require, select, send, sleep, study, system, tell, tie, time, until, use, wait, while, write.