Unsurprisingly, it's similar in Scottish Gaelic and Welsh. Mandarin and Cantonese (and probably other Sinitic languages) don't either, with much the same arrangement as the Celtic languages.
There are many yes-like words, but not exactly "yes". There's "it is", "it's correct", and "it's good" that may be used depending on context to mean yes.
Amazing! I wonder about the universality of head nods (for yes) and head shakes (for no), and whether languages that lack a "yes" or "no" might still use nods.
> There are several exceptions: in Greece, Iran, Turkey, Bulgaria,[2] Albania, and Sicily a single nod of the head up (not down) indicates a "no".
Though for Bulgaria at least it seems it's shifting with many people who lived abroad at some point(myself included) and have picked up the correct/more universal form. Which makes it worse: Now no one really knows whether you mean yes or no...
There's also the head bobble, common in south India, which looks a lot like an ongoing head shake but generally means something like ongoing agreement.
Referring to it as "ongoing agreement" reminds me of something I think of as the "confessional no." When addicts talk about their addiction, there's often a rhythmic shaking of the head from side to side like a continual "no," but that speeds up and slows down with some relationship to the grammar of the sentences used.
You can probably make yourself do it by saying out loud: "When I was young, I thought I understood everything." It's like an ongoing disagreement.
