Declension class fi:solakka

I wrote it the wrong way. Should read: If you google any word in this declension class, you'll mostly get at least hundred times as many hits for single-k-form than for the double-k-form.

It's strange, because normally the illative plural has the strong grade doesn't it? I wonder why there's this exception. Anyway, I've swapped the forms around. Should the same be done for the laatikko class?

Indeed it seems that also in "laatikko" class the single-k is more popular. Here are numbers from Google searches: laatikoiden 114 000, laatikkojen 9 800, laatikoitten 3 600; laatikoita 242 000, laatikkoja 10 000; laatikoihin 78 000, laatikkoihin 6 600; laatikoina 10 000, laatikkoina 3 400; laatikoineen, laatikkoineen. If one chooses another word, one gets different result. With "valikko" the frequencies are more even (ratio is btw. 1 and 2), and in comitative the double-k form is more frequent.

Forgot laatikoineen 8 000, laatikkoineen 4 000. Also in "puolukka", puolukoineen is much more popular than puolukkoineen.

I wrote KOTUS about this. Their comment: good observation, but we cannot change the system right now. I take this as support.

For the record, the historical background is that coda *j used to trigger gradation of geminate stops in some Finnish dialects (IIRC there's no evidence for gradation of singletons), but it's been mostly analogized away from existence; in particular since plural & past tense *-j has often contracted with the preceding vowel to -i-. (This has included even *oi-stem nouns such as > dial. kukoi for kukko.) However, -kka always takes the plural stem -kkoi-, so gradation to -koi- had pretty good odds for remaining.