Sayings in your native language that makes seem weird in english.

[Archem]

Thats different. You say the pig thing like in being negative. "You are only going to study when pigs fly." Pocketknives thing is like positive "You studying? zomg pocketknives shall rain"
Or something.

I see now. There's one that fills that bill in English, however, I can't recall how the expression goes right now.

[fruckert]

Um
It's on the tip of my tongue
And I can't remember it
Arseface

[Djanki]

I got a new one!

"Cuando Colon baja el dedo"

It means "When Columbus lowers his fingers".
It references an old statue of Christopher Colombus ('Cristobal Colon' in Spanish), which has the man pointing off to the distance. It's akin to 'when pigs fly' or 'the chickens come home to roost'.

[Cerebus]

"Il pleut des clous." (It's raining nails.) It actually means the same thing as "It's raining cats and dogs."

"...quand les poules auront des dents." (...when chickens will have teeths.) It actually means the same thing as "...when pigs will fly."

"Un plan de nègre." (A ****** plan.) This one seems a little racist, though. I think it means a bad plan or something like that. I rarely heard this one.

There are more, but I don't remember... J'ai un blanc de mémoire...

[Djanki]

New one:

"Vocalobo". It means 'wolf's mouth'. It's used whenever talking about a really, really dark place ("Dark as a wolf's mouth")

[Archem]

"Un plan de nègre." (A negro plan.) This one seems a little racist, though. I think it means a bad plan or something like that. I rarely heard this one.

"Negro"? Not "black"? Because it would make sense if it meant "black", since referring to something as "black" generally has a negative connotation.

[Red Giant]

"A Wolf in Sheeps Clothing" - Someone who is dangerous in some way but who is pretending that they are harmless or friendly.

[Archem]

Like a man driving an ice cream truck. I don't trust a large, ugly man who drives a van and spends all day offering little kids treats.

[Cerebus]

"Negro"? Not "black"? Because it would make sense if it meant "black", since referring to something as "black" generally has a negative connotation.

Nope, it's negro. But negro means black in Spanish or something like that, so it's quite the same, except that it sounds a bit more racist...
Anyways.

"A Wolf in Sheeps Clothing" reminds me of "Une main de fer dans un gant de velour." which would translate to "An iron fist in a velvet glove."
I'm not sure about the meaning, though... maybe it's the same thing as the wolf one.

[fruckert]

I like an Iron First in a Velvet Glove
It's very poetic

I had one but I can't remember it
Although I think I remembered the negative version of "When Pigs Fly"
When Hell Freezes Over

[Archem]

[fruckert]

Well I be damned
That=Awesome

[Talt]

Like a man driving an ice cream truck. I don't trust a large, ugly man who drives a van and spends all day offering little kids treats.

ROFL

That reminds me cartoons like Dexter's Lab...


Oh, and you guys maybe will lol at this:
Standart brazilian ice cream truck
Little smaller, eh?

[fruckert]

Just a little

[Archem]

Yeah, they have those about the more Hispanic parts over here. I should know. Up until a few years ago, I had never actually seen an ice cream "truck".