To be on the wooden path

As in: "You thought those two were together? Christ, you must have been on the wooden path"

German: "Auf dem Holzweg sein"

Meaning: translates rather well to the English "to be on the wrong track". Why the mention of a "wooden path" in particular? The saying seems to date back to Medieval times when the wood- and marshlands of Germany were full of "Holzwege" - rudimentary paths consisting planks of wood or logs laid over bare earth and swamp. Such paths served to enable woodcutters to cart back a larger number of logs and branches at a time, and tended to culminate in a cul-de-sac deep in the forest. Pilgrims and travellers who followed such wooden paths would thus be led not out of the woods, but rather find themselves getting more and more lost. 

On a personal level, I generally find wood-based metaphors linked to cognitive ability somewhat amusing. My favourite has to be "as thick as two short planks", or just the term "plank" - used to describe someone distinctly mentally underendowed...

If necessary, the devil will eat flies

As in: "You walked 5 miles home last night? / Well I missed the last bus. If necessary, the devil will eat flies"

German: "In der Not frisst der Teufel Fliegen"

Meaning: comparable to the English "Beggars can't be choosers". Why on earth might the Devil need to feed on anything at all? Well, apparently the Aramaic word for "devil" is "ba'al-debaba", which literally means "Lord of the Flies". In this context, "In der Not frisst der Teufel Fliegen" would seem to describe a situation of the Devil being in such desperate need or want that he might eat his own offspring. That's one of about seventy-five million theories, anyway - a number of other explanations invoke metaphysics, which I find too boring to mention here.

Variants: "Hunger is the best cook" (German: Hunger ist der beste Koch)

To have your canal full

As in the sentence: "It's time to head back, you've got your canal full already"

German: "jemand hat den Kanal voll"

Meaning: "to get drunk". Refers unfortunately not to a Northern German obsession with man-made water channels but instead to the various components of one's digestive system (oesophagus, stomach etc) and their propensity to fill up after a night of chugging down booze (though the saying has featured in the headlines of many a German newspaper story about people falling into canals after a night out - who says the Germans don't have a sense of humour!). Perhaps comparable to the sayings "well-oiled" or "tight as an owl", though alas the imagery is less vivid in German. 

Variants: too plentiful to name. 

To go someone on the biscuit

As in the sentence: "You go me on the biscuit, I do wish you'd go away."

German: "jemandem auf den Keks gehen"

Meaning: "to annoy someone". Variants include: "to get on someone's nerves" (jemandem auf die Nerven gehen), "to get on someone's bag" (jemandem auf den Sack gehen), and "to get on someone's spirit" (jemandem auf den Geist). On no account should it be mixed up with biscuit-themed English sayings such as "to take the biscuit", which means something else entirely.

The yellow of the egg

As in the sentence: "You are the yellow of the egg!"

German: Das Gelbe vom Ei

Meaning: The right thing, the best, the right way of doing something. Used sometimes in advertising. Also can be used with negation - "nicht das Gelbe vom Ei" : "nothing important."

To only understand train station

As in: "I only understand train station"

German: "nur Bahnhof verstehen"

Meaning: somewhere between "it's all Greek to me" and "I don't care", conveying both incomprehension and disinterest at the same time.

A quick description

A collection of German sayings translated literally into English. I've going to try and post one a day. Enjoy!