to wait on: to serve in a store or restaurant Examples of WAIT ON You should arrive on time, because the job interviewer won’t want to wait on you. The hockey players had to wait on the last game to end before they could start.

you never know: You say you never know when you mean that it is possible that something might happen although it seems very unlikely:Examples of YOU NEVER KNOW Because you never know when you’re going to get an urge to knit in a dark place. You never know who’s going to show up on the…

back and forth: in a backward and forward motion Examples of BACK AND FORTH She and I went back and forth, continually trading ideas, but we never reached an agreement. My job has me going back and forth between Atlanta and New York right now.

all of a sudden: suddenly, without warning (also: all at once) Examples of ALL OF A SUDDEN It seems like, all of a sudden, you’re mad at me, and I can never figure out why. All of a sudden, the storm subsided and the rain stopped.  

on the other hand: however, in contrast Examples of ON THE OTHER HAND On the other hand, registered voters may participate in any primary they choose. Kidney inflammation, on the other hand, is rare, but no treatment exists for it.

to wake up: to arise from sleep, to awaken Examples of TO WAKE UP I hit my snooze alarm over and over again, because I didn’t want to wake up. The voters of this district need to wake up and realize that Governor Stevens isn’t doing a good job.