Things you CANNOT do

Wear your ❤️ on your sleeve

Eat your heart out.

Laugh till you cry!

Eat till you burst!

Laugh on the other side of your face.

Come up the Clyde on a biscuit.

Be on cloud 9

Be on top of the world

Disappear up your own backside

You can't walk on air. Even if you're wearing those very expensive innersoles in your shoes.

Ah, how dull our language would be without such expressions

Be a ray of sunshine.

Thanks for reminding me phoenix
Sleep on a washing line is not the sole example already posted that has an origin in historical fact.

Love you to bits.

My mother used to say "Get your nose out of that book!"

the ?

Get you knickers in a twist the Phoenix would know about that one ?

CherryCezzy

Walk on air.

Sleep on a washing line.

Sorry, CherryCezzy, but the "sleep on a washing line" thing has some historical fact. People who couldn't afford a bed in a bunk house, were given a cheaper option of being able to drape their arms over a rope slung across the room, and sleep that way.

For the Glesca Grannies , remember the old clippies saying
come oan, get aff (Come on, get off my tram!)

Turn green with envy

Carry the world on your shoulders.

Love it, great thread.

Needed that, unlike a fish needs a bicycle.

Literally, I shall continue to use metaphors when appropriate.

Have a head that buttons up the back.

See right through someone.

Pay through your nose (not yet anyway).

Eat an elephant one bite at a time.

You can't be knocked down with a feather

Blow up like a balloon (unless a bicycle pump is inserted ‘somewhere’)
Laugh like a drain