Welcome to our list of idiomatic expressions - Let us help you study English! These types of phrases are used by native speakers daily. Learn these idioms and you will be on your way to speaking English in a more natural way :)

Under construction:
Being built or repaired. ex. "This road has been under construction for six months."

Under fire:
Being attacked. ex. "The soldiers came under fire when they approached the city."

Under the table:
Illegally. ex. "Many illegal immigrants try to find work under the table."

Under the weather:
Sick. Ill. ex. "I'm feeling a bit under the weather today."

Up and about:
Recovered from an illness. ex. "Hey it's nice to see you up and about. You must feel a lot better."

Up for grabs
Available for anyone to try to get. ex. "The Chinese telecom market is still up for grabs."

Up in the air:
Uncertain. ex. "His future at this company is up in the air."

Uptight:
Conservative, nervous, nit-picky. "Stop being so uptight, relax a bit!"

Up to it:
Capable of, fit for. ex. "Do you feel up to playing a game of tennis?"

Up to one's neck in something:
Very much involved in something. To have a lot of something. ex. "I can't go out tonight. I'm up to my neck in work."

Up to par:
Meeting normal standards.

(To) use every trick in the book:
To use every method possible.