りんごの半分が腐っている。

apple (fruit); apple tree (Malus pumila)

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

half

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

to rot; to go bad; to decay; to spoil; to fester; to decompose; to turn sour (e.g. milk); to corrode; to weather; to crumble; to become useless; to blunt; to weaken (from lack of practice); to become depraved; to be degenerate; to be morally bankrupt; to be corrupt; to be depressed; to be dispirited; to feel discouraged; to feel down; indicates scorn or disdain for another's action; to lose a bet; to be drenched; to become sopping wet