Idioms are one of those things that are nearly impossible to translate directly, so when I speak English, I don't use idioms from my native language - I use the English ones. Anything else would just sound like an illogical mess.
That said, let's have fun with directly translating Swedish idioms! Picking a few of my favourite ones - there are hundreds and hundreds to choose from. I use most of these regularly in daily conversation.
Jag anar ugglor i mossen
"I suspect there may be owls in the bog". Means: something strange is going on, and I am suspicious.
Tomtar på loftet
"Gnomes in the attic". Means: being a bit crazy. To have gnomes in the attic means you're a bit of a kook.
Ingen fara på taket
"No danger on the roof". Means: There is nothing to worry about. See also, det är ingen ko på isen/ there is no cow on the ice.
Att gå över ån efter vatten
"To go across the river to fetch water". Means: to go through needless trouble or complications to carry out a task that is actually easy.
Ropa inte hej förrän du är över ån.
"Don't shout hello before you are cross the river". Means: don't celebrate before you have accomplished what you set out to do.
Andra bullar
"Different buns". Usage: "Han ska få se på andra bullar" / "I'll show him different buns". Means: to drastic change to how you approach something. Oh, he made me angry, next time I see him it will be andra bullar!
Bakom flötet
"Behind the fishing float". Means: to not understand what's going on/to be a bit stupid. Regionally also a rude way to call someone mentally disabled.
Gå på i ullstrumporna
"Keep walking in woollen socks". Means: either to keep doing what you've always done without being bothered, OR to keep running your mouth in a sensitive situation.
Det brinner i knutarna
"The corners of the house are burning". Means: we are running out of time and have to get this done right now.
Elda för kråkorna
"To keep a fire going for the crows". Means: to be wasteful. Specifically about heating your home; i.e: keeping your door open when the hearth is burning, letting all the warmth out.
I bara mässingen
"In nothing but the brass". Means: naked.
Akta sina löss för snuva
"To keep your lice from getting colds". Means: to be very careful and avoid negative consequences, especially being caught up in other people's actions.
Ligga i lä
"To be down-wind". Means: to be inferior to someone else.
Nu är det kokta fläsket stekt
"Now the boiled pork is fried." Means: this has turned very bad; an unavoidable catastrophe is coming.
Se sig i månen efter något
"To look to the moon for something". Means: to ask for the impossible.
Sitta hemma och uggla
"To sit at home and owl". Means: to not do anything at all; to be lazy; to avoid company.
Som Fan läser Bibeln
"As Satan reads the Bible". Means: to purposefully misinterpret something.
Trolla med knäna
"To cast spells with your knees". Means: To attempt the impossible with very small means.
Ögonaböj
"Bend the eyes". Means: Immediately!
