Which word in the English language has three consecutive sets of double letters?
And the answer: bookkeeper.
While many words have three pairs of double letters, such as "Mississippi," very few have them right after each other. With their double O, immediately followed by a double K and double E, the words "bookkeeper" and "bookkeeping" are unique in the English language.
Think about it: how many words with consecutive double letters can you name? While words containing double letters are extremely common (we've already used two in this sentence alone), "bookkeeper" is a unique example of three sets of double letters. Most other words that contain such a sequence of repeating letters are broken up by a hyphen, such as "sweet-toothed."
Words in other languages don't follow these same rules, however. French, for one, is a language frequented by double and sometimes triple letters – the latter being a convention that is not found at all in the English language. Take, for example, the verb "créer" in French. In the past participle form of the word, it takes another "e," making it read "créée" and translating to "created." Other Romance and Germanic languages also incorporate a third, repeating letter when conjugating a verb into past tense.
Meanwhile, the English language enjoys other odd conventions. Only four letters (A, E, O, L) are doubled at the beginning of a word (e.g., aardvark, eel, ooze, llama), and yet more words start with double O than any others in the English language. How many can you name?
Read more about double lettered words here.