Hold someone accountable for

Example

I hold you accountable for taking care of my niece Emma

It costs an arm and a leg

Example

This concert tickets cost us an arm and a leg

Under the weather

Example

This morning I am a little under the weather, I am calling to take sick leave

Stand someone up

Example

Sandra has stood me up again, I won't ask her to go out with me again.

Make short work of something

Example

We made short work of the assignement, because we didn't want to miss the plane

Have someone on the string

Example
Everybody thought I've got him on a string, but it wasn't truth

A sucker for

Example

My girlfriend is a sucker for for fantasy movies

Leave me alone

Example
I'm sick of the way you treat me, leave me alone!

Spark off rebellion

Example

Tax raise sparked off rebellion

Build castles in the air

Example

At the end of summer i like to build castle in the air for the next season

By fluke - stroke of luck

Example

A woman who is successful, it is not by fluke or fate, it is so because she has decided it

Hope springs eternal

Example
I don't want to hear negative stuff, we are sad, hope springs eternal and where is hope there is God

Keep one's head above water

Example

Despite the scandals and accidents  the team has managed to keep their head above water so far

To skip something

Example
Your remark is unnecessary, skip it ..

To break loose from

Example
For those who want to break loose from the chains of smoking, there is hope