User:Surjection/Finnic sporadic alternations

m ~ v
Probably actually *m ~ *p/*b > m ~ p/v, in some cases m ~ v (invariant), perhaps by levelling, or already reflecting earlier *m ~ *b. Sound-symbolic feature?

Sporadic (un)gemination
Noted by SKRK, often geminated when preceding a (usually final) short vowel, often /. Some cases may be explained by suffix substitution.

Ungemination by derivational suffixes

 * : &rarr;, dialectal   &rarr;
 * : dialectal &rarr;,   &rarr;
 * : ? &rarr;,   &rarr;