>>858
Do you have a Japanese grammar book? (I know, I know, it's funny considering your first example) it should explain this stuff
日本語の本が見つからない
the verb here is the 'non-grammatical' passive
you can put verbs in the passive form by adding -られる to the stem of 一段 verbs or -れる to the negative form of 五段 verbs. for example there's (I'm going to copy stuff from the dictionary):
見つける (v1,vt) to discover; to find
its grammatical passive:
見つけられる (potential or passive)
but it's also paired up with a 'lexical passive'
見つかる (v5r,vi,uk) to be found; to be discovered
Knowing this it becomes clearer why the book is the subject (が)
in your example. It's "the book can't be found" instead of "I can't find the book". Note that it says 'vi' (intransitive verb) next to the dictionary entry. There are many such intransitive-transitive verb pairs.
http://www.sf.airnet.ne.jp/ts/japanese/message/jpnEUwEoW7XEUhMPq0e.html
The end result is that there are too many possible ways to say 'I can't find this stupid book!!' so certain forms have become privileged. I don't know how that happens sorry; ease of use, ancient grammar...? The passive form has also other uses like implying a negative result:
雨が降ってきた "It started to rain."
(私が)雨に降ってこられた "It started to rain" (implication that you got wet)
differentiate 分ける(vt)/to be differentiated (to understand) 分かる(vi)
is a little trickier but it's similar to the first example
wakeru -> do you differentiate between this kanji's readings and other readings?
wakaru -> is this kanji's reading differentiated (understood) (from that of other kanji)?
does seeing it this way help?
There's also using the particles to mark the agent/patient that'll you want to know but it's all in grammar books
they're boring but useful...