ある is listed in dictionaries as having ラ行五段活用, which would suggest a negative form of あらない. However, that form does not exist. Why not?
I thought when you get a type one verb ending with "ku" you replace it with ita. For example Kaku (to write) goes to Kaita. So I'm guessing Iku is an exception, does this happen with other verbs too ? ...
"It seems there is none" is なさそう, which escapes the usual rule for 形容詞 (イ-adjectives), which says "drop the い and add そう". Is there a historical explanation for this exception? And does it have ...
There are verbs with irregular humble forms, e.g. the humble form of 借りる is 拝借する. For these verbs, are the "normal humble conjugations" still used, or considered grammatical? Would お借りする be ...