Patronize What is the american pronounciation? /pei/ or /pa/?

impromptu speech or improvised speech? which one is more acceptable in the US?

irrevocable and irrecoverable the difference?

shudder,shiver,tremble,quake,quiver the differences

buff boy, what's the meaning? and what about "back of of class crew"? and what about "no notion"? and "pervs"? and" class bunkers"? and

swindler and scammer, the difference?

runneth over what's the meaning ?and how to use it?

goods,merchandise,commodity the difference

on occasion，on occasions which one is correct