- panecillo (Although this one has most of the time another meaning...)
I know short question, but seemingly difficult for me. Is there a definitive diminutive form?
Are there multiple accepted forms?
In Mexico is well addressed as panecito, and I think anyone would understand it, however is not a real word as far as I know, at least couldn't find it on the dictionary, I found this however:
"Pan" is a generic term, it means bread in general, not an actual piece of bread. In this sense you would not use it in diminutive form, would you?
Panecillo (a small bread baked in that form, not a slice) is itself a word. You could say "panecillito" for a small "panecillo".
So, for "pan" (any kind of "bread") I would say "pancito" or "panecito". "Pansito" and "panesito" are wrong.
Here in Perú I was taught and learned it this way:
I memorized the key: "REN(cito)" -- Meaning when a word ends in "R", "E" or "N" append "-cito" (masculine) or "-cita" (feminine). Otherwise, words ending in "O" or "A" likely get "-ito" (masculine), "-ita" (feminine), or seemingly less common "-illo" (masculine) and "-illa" (feminine).
Therefore, and confirmed by what is practiced here in Hauncayo, Perú we say Pancito to refer to a smaller piece of bread or smaller roll.