"Watch your back" means "Look out for what might be behind you." "I'll watch your back" means "Don't worry about what might be behind you, I'll take care of that."
Keep an eye out for buttermilk. I can't find it in the shops so keep an eye out for it and if you see some then please buy it!
The babysitter should keep an eye on the kids.
To keep an eye on means to watch.
To keep an eye on means to watch
It hits you twice, a double blow or set back.
"To be" is not an idiom - it's a verb.
Pest is not an idiom. It's a word.
The idiom "apple shiner" means the teacher's pet.
The meaning of the idiom in the pink of health means being in good health.
That is when somebody does something to you and you do the same back to him or her.
Meaning being in desperate straits
The meaning of the idiom "to slap the back off you" is fairly straightforward. It implies an exaggeration, that one would slap someone else so hard that their back would come off.
It hits you twice, a double blow or set back.
"To be" is not an idiom - it's a verb.
The idiom 'break one's back' means that they won't do anything to exert themselves.
Shortchanging means giving back less than something is worth.
Pest is not an idiom. It's a word.
The idiom "apple shiner" means the teacher's pet.
The meaning of the idiom in the pink of health means being in good health.
Like water off a duck's back means unfazed, taking things in stride, unbothered.
The idiom means impress someone is egg on