Relevant grammar question & comments here (sixth post).
Formed from verb-te + yamanai. (Note that Vte is usually associated with feelings & desires). Vte = Verb, -te connective form.
This expression is normally used in written Japanese; not conversaitonal Japanese. I think this belong to Class 3.
class 3 as in sankyuu? it seems more 1-kyuu to me, esp if only used written?
Sorry, I made a mistake - I meant 1-kyuu.
〜てやまない. This is often used with words such as 求める, 希望する, 祈る and 願う.
This grammar is indeed for 1kyuu and does not always belog to the written language. If you hold a speech the form "-teyamimasen" 「てやみません」 It comes from the word「やむ」that means stop. For example you can say 「雨いつごろやむかな」, which corresponds to when you in English want to say "When will it stop raining, I wonder". Or this A>「あれ、ピアノの音がやんだ。レッスン終わったんだ」Eh? The sound of the piano stopped. The lesson is over. B> 「そうね」Yes, indeed.
I think ex #3368 doesn't really belongs to this category, rather it belongs to the verb 「やむ」、although this grammar comes from the word 「やむ」。