When he was in college in the United States, my English father-in-law told a woman he’d met: “I’ll knock you up sometime.” She slapped him. In British English, to knock someone up means to call on someone, particularly to wake a person by knocking at the door. (In the Victorian era, a knocker-up was a living alarm clock, going door to door to rouse people so they made it to work on time). In American English, of course, it means to get a woman pregnant. He thought he was proposing a date; she imagined a lot more than that. This is perhaps my favorite proof that Britain and the US are “two countries separated by a common language.”
Usually the vocabulary differences are less fraught, though they may still lead to confusion. An apartment in America is a flat in Britain. Eggplant and cilantro are aubergine and coriander respectively. Cars have bonnets and boots in the United Kingdom, not hoods and trunks. People wear jumpers there when we’d put on a sweater. A mean American is cruel; in Britain, a mean person is stingy. These differences can often be worked out from context, and are unlikely to offend.
Some, however, like knock you up, have the potential to embarrass. Having been married to a British person for many years now, I’d like to share my own list.
The No. 1 problem word is pants. I’ve often found myself saying to various people “Oh, I’ve spilled something on my pants!” or “Where did you get your pants?” In the US, this works fine, since pants means “trousers.” In the UK, though, pants refers to underwear, and “I like your pants!” is a compliment that just makes people uncomfortable.
Another word that can cause trouble is toilet. Americans ask “Where is the bathroom?” thinking it is not polite to inquire about the “toilet.” Though we use the word to refer to the thing itself, we otherwise prefer the euphemism, even when, as countless British people have pointed out, there is no bathtub anywhere near the room. For many people in the UK, however, “Where is the toilet?” is perfectly proper. The word carries some class baggage, though, as many words do in Britain. Using it generally marks a speaker as middle class, while upper-class speakers prefer loo.
In my children’s eyes, the worst offender is biscuit. We know a biscuit as a kind of savory roll generally leavened with baking powder or soda. In Britain, biscuits are cookies. My children declined “biscuits” for years when kind people offered, thinking they were about to get a dinner roll instead of a delicious piece of shortbread. They no longer make this mistake.
I think this is all quite interesting. In America, that’s a pretty enthusiastic endorsement. In Britain, it’s not.