As touched upon in another thread, there are several nouns that exhibit a kind of vowel shift in older forms, where the ending vowel is fronted when the noun is used on its own to become /i/ or /e/, ...
This is somewhat related to the discussion of classical auxiliary verb ふ, mentioned in the answer to snailboat's question, What is the わ in 忌まわしい and 嘆かわしい?. Another apparent iterative / repetitive ...
In English, we have prefixes, like "pre-"; suffixes, like "-ize"; and arguably, expletives that function as infixes (one classic example is "abso-fucking-lutely"). In Japanese, we also have ...
Many verbs come in pairs, frequently but not always transitive/intransitive pairs. These verbs generally have multiple okurigana characters, but according to my dictionary one of the pair was formerly ...
On chat, Chocolate helped me find some examples of adjectives produced from verbs using the しい suffix. In the following examples, it appears to attach directly to the 未然形: 勇む → 勇ま ＋ しい 悩む ...