半

半 (bàn) means 'half' and functions as a number-like modifier. It comes after a whole number and a measure word to mean 'and a half' — 一个半小时 ('one and a half hours'), 两年半 ('two and a half years'). It also comes before a measure word alone to mean 'half a __' — 半个苹果 ('half an apple'), 半杯水 ('half a glass of water').

The most common everyday use is in telling time: X点半 means 'half past X' — 七点半 ('seven thirty'). 半 can also mean 'partly' or 'half-' in compounds: 半天 ('half a day' or, idiomatically, 'a long while'), 半夜 ('midnight / middle of the night'), 一半 ('one half'). Two notes for English speakers: 半 must take a measure word when modifying a noun, and 半 + verb often means 'halfway' (说到一半 'halfway through speaking').