Last night I had a dream, and I don’t remember why but at some point in the dream I uttered the word “mathish”.

In the dream, it occurred to me that the English suffix “-ish” might be descended from the same root as the Greek suffix “-ικος” (aka, “-ic”, a suffix which we borrowed into English and use extensively). In the dream I recalled a linguistic rule that causes k sounds to turn into sh (softening: a k or g sound followed by a vowel where the tounge is forward in the mouth often ends up turning into an s, z, sh, or th). I recalled that in our word mathematician, the “ic” is pronounced “ish”, so this process still happens today. And, still in the dream, I wondered if Latin had a similar suffix, and recalled the word amicus (“friend”).

When I woke up I looked up the origins of those suffixes and sure enough I was right.

My only mistake was, there was a minor wrinkle I didn’t anticipate: “-ish” actually descends from a composition of two suffixes, but one of them was indeed the same one that became “-ic” in Greek.