時間がたつのに気がつかなかった。

time; hours

indicates sentence subject (occasionally object); indicates possessive (esp. in literary expressions); but; however; still; and

to rise up; to initiate (political) action

indicates possessive; nominalizes verbs and adjectives; substitutes for "ga" in subordinate phrases; (at sentence-end, falling tone) indicates a confident conclusion; (at sentence-end) indicates emotional emphasis; (at sentence-end, rising tone) indicates question

at (place, time); in; on; during; to (direction, state); toward; into; for (purpose); because of (reason); for; with; by; from; as (i.e. in the role of); per; in; for; a (e.g. "once a month"); and; in addition to; if; although

to notice; to become aware; to perceive; to realize; to realise; to be scrupulous; to be attentive; to recover consciousness; to come to oneself