っぱい — is this only used for taste words like 酸っぱい, or does it apply more broadly?

Question

酸っぱい (sour) and 塩っぱい (salty) are the only っぱい words I actually know. Is this suffix mainly locked to a small, fixed set of taste adjectives, or is it a genuinely productive pattern I could attach to other nouns to mean 'full of X'?

Accepted Answer

You're right that in practice it shows up most in a small cluster of taste/sensation words (酸っぱい, 塩っぱい, and colloquially 湿っぽい-adjacent forms), but the underlying idea — 'saturated/full of the quality of X' — is the same root as words like 力いっぱい (with all one's strength, lit. 'full of power') and 精いっぱい (to the utmost). So it's less a fully open, freely-combinable suffix at the beginner-facing level, more a recognizable pattern that shows up in a specific family of fixed expressions once you know what to look for.

Answer

力いっぱい clicking this into place for me too — I'd always memorized it as a separate vocab word without noticing the っぱい inside it.