Every language has a few phrases that don't always translate well — and British English has some absolute corkers.
"A few sandwiches short of a picnic"
Someone that lacks common sense might be described as "a few sandwiches short of a picnic." The phrase was first documented in the BBC's "Lenny Henry Christmas Special" in 1987.
"She's great fun, but she's a few sandwiches short of a picnic."
Although it's more often used as a synonym for raincoat, an anorak is something slightly different in playground slang. Someone that's a little bit geeky, with strong interests or expertise in a niche area, might be referred to as an "anorak." This probably originates from the "uncool" appearance of anorak coats and the people wearing them. "Thomas is such an anorak when it comes to train trivia."
Calling "bagsy" is the equivalent of calling "shotgun" or "dibs" when something, like the front seat of the car, is offered up to a group. Schoolkids might call "bagsy" on items from their friends' pack lunches, like an apple or a cereal bar, that the friend isn't going to eat. "Does anyone want thi—"
This phrase became mainstream in the USA in the 1920s despite its British origins, but its popularity in the States has dwindled since the turn of the century. The "bee's knees" referred to small or insignificant details when it was first documented in the 18th century. Since then, the phrase has evolved and refers to something at the "height of cool." "The Beatles are the bee's knees."
To "pull a blinder" involves achieving something difficult faultlessly and skilfully. The phrase is most commonly used when the individual has been lucky and the person saying it is in disbelief that the first person has managed to pull it off. "And did you see that equalising goal in the last minute of injury time? He pulled a blinder there."
"Bob's your uncle"
The very British equivalent to "Hey presto!" or "Et voila!" This phrase is used to describe a process which seems more difficult than it actually is. "Press down the clutch, put it into gear, then slowly ease off the clutch again. Bob's your uncle — you're driving!"
Something that is "bog-standard" is completely ordinary with no frills, embellishments, or add-ons. Its origins are somewhat unclear, but a "bog" is another word for a toilet in British slang, adding to the connotations that something "bog-standard" is unglamorous and unspecial. "How was the hostel?" "Oh, nothing exciting to report. Just your bog-standard dorm, really."
The "boot" is the compartment at the back of the car known as the "trunk" in American English. "Shove the shopping in the boot."
An informal way of asking someone to make room where they are sitting for you to sit down, too, would be asking them to "budge up." It's similar to "scoot over" or "move over." "Hey, there's loads of room on that bench. Budge up and make some room for us, too!"
The name of a strongly-brewed cup of English breakfast tea with milk — the way that tea is most commonly drunk in the UK. It's common courtesy to offer a labourer or builder working on your house a builder's tea while they're working — especially if they're working out in the cold. This is probably how the term came about. "A bacon sandwich and a builder's tea. Now that's a proper breakfast."
A "good old chinwag" is a good chat, catch up, or gossip with someone. The action of chatting away — with the jaw bobbing up and down — resembles a chin "wagging" like a dog's tail. "Those two are having a proper chinwag — I haven't been able to get a word in edgeways for half an hour!"
Something untrue — often made up for dramatic effect. Although no one is completely sure of the word's origins, it could derive from the words "cod" and "wallop," which historically meant "imitation" and "beer" respectively — implying that "codswallop" is the kind of rubbish you make up when drunk. "Oh, what a load of codswallop!"
"Cost a Bomb"
Expensive. "Your watch is gorgeous." "I should hope so, it cost a bomb."
Cockney rhyming slang for "knackered," if you're "cream crackered" then you're incredibly tired. A "knacker" was the person that slaughtered worn-out horses in the 19th and 20th centuries for their meat, hoofs, and hide. So, if you're "ready for the knacker's yard," you're exhausted beyond relief.
"This week's done me in already, and it's only Tuesday. I'm cream crackered."
A "dog's dinner" is a mess or fiasco — sometimes also referred to as a "dog's breakfast." "You've made a dog's dinner of that."