"Somebody Stupefied a Death Eater on top of the Tower after Dumbledore died. There were also two broomsticks up there. The Ministry can add two and two, Harry."

Harry Potter and the Half-Blood Prince

I deduce that "add two and two" is a variant of put two and two together. If so, any reason why it's been "two and two", not "one and one", etc. "One and one" looks more simple.

  • 1
    I think "two and two" is used as it's just generally considered the easiest non trivial sum. Similar to the phrase when 2 + 2 = 5 – Gamora Aug 12 '19 at 14:23
  • 1
    What @Bee said. To my mind, to be able to add two and two (or to know two and two make four) - plus the pejorative negated versions (not to be able to do the trivial sum) would be the "original" forms. Being able to put two and two together is a later derived "idiomatic" usage (that actually usually refers specifically to drawing conclusions from two single things both occurring, not two pairs of things). – FumbleFingers Aug 12 '19 at 14:34
  • ...compare also He knows how many beans make five (he's not a complete idiot; in fact, he might be reasonably smart). But all such expressions are inherently "slangy", and may vary across different (geographical or social) linguistic subsets of the worldwide Anglophone population. – FumbleFingers Aug 12 '19 at 14:38

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.