Is "add two and two" an idiom?


"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.


Posted 2019-08-12T14:14:48.440

Reputation: 12 255


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

– Bee – 2019-08-12T14:23:46.380

1What @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 Reinstate Monica – 2019-08-12T14:34:54.893 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 Reinstate Monica – 2019-08-12T14:38:15.860

No answers