wait on = to serve someone, usually used in restaurants.

Cindy waits on tables part time to help pay for college.

 

wait up = wait; wait until one person is at about the same place.

I told my kids to wait up before they got to the water.

walk off with = steal; take someone without permission.

He tried walking off with a bag full of money that he stole from a bank, but soon he was caught.

 

walk out on = leave a person; leave a movie because it's bad or boring.

After fourteen years of marriage, Helen walked out on her husband because she met another man.

warm up = prepare for something, usually for a game other physical activity; get ready.

She usually warms up by stretching her legs before she runs.

In the winter, I need to warm my car up before I drive it.

 

watch out = be careful; look for something dangerous

This sign is telling drivers to watch out for road construction.

"Watch out! You might get hit!"

You have to watch out for other drivers when you're on the highway.

wear out = to get old or to be used too much.

When the soles on your shoes wear out, you should think about buying a new pair.

wear out / wore out / worn out

what's up = hi; How are you? What's going on? What's happening? (very popular)

A: Hey, Darrel! What's up?

B: Not much. What's up with you?

A: Nothing. What are doing?

wipe off = to clean; to clean tables, chalkboards, whiteboards

The teacher uses an eraser to wipe off the chalkboard.

work out = to be good; to be okay; to have success.

Brian got a new job last week and it's working out for him and his family's schedule very well.

I bought a Dell personal computer a couple years ago, but it never really worked out for me. In fact, it was a terrible purchase. Now I only use Apple computers. (Don't buy a Dell!)