back and forth = to go between two places, again and again.

He bikes back and forth between his job and his apartment every day.



 back up = to support, to help someone

Robert plans to back up his wife when she delivers her baby. (used as an infinitive)


If he is unable to drive her to the hospital, they have a back up plan. His brother can drive her there. (used as an adjective)

having fun

be at it = to do something; to practice or learn how to do something.

A: They love to play with those blocks.

B: Yeah, they’ve been at it for the last hour.

(Note: This idiom is often used in the present perfect tense)


bend over backwards = to work hard at something; to try to help someone.

The government bent over backwards to get the I-35W bridge rebuilt.


 better off = in a situation that is good–better than before.

Jen thinks she’s much better off with her new boyfriend. Her old boyfriend wasn’t very nice to her.

two people

break down = a machine stops working, usually used for cars

Tim’s car breaks down all the time. He has to get a new one.

This is the third time it has broken down this week. (present perfect)

man with car problems

bring up = to say something; to introduce a topic for conversation.

If you have chest pains that don’t go away, you should probably bring that up with your doctor next time you see him.


 break up = 1. to make something small; 2. to end a relationship.

She got a phone call from her boyfriend. He told her he wanted to break up with her. (definition #2)

woman on cell phone

bump into = meet someone you know by chance or by accident.

On the way home from the store, Alice bumped into an old friend she hadn’t seen in years.

two friends

by the way = This idiom is used when you want to introduce something new in a conversation. It’s usually off topic.

"Juggling is easy for me. I’ve been juggling for years. By the way, I also know how to do backwards somersaults."


man juggling

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