adverb, noun
Used as a noun or adverb to indicate exactly one half of something, or a partial amount. Very common in everyday speech.
ケーキを半分に切ってください。
Please cut the cake in half.
仕事はまだ半分しか終わっていない。
Only half of the work is done yet.
Standard kanji spelling; high-frequency word.
半ば is more literary and often means 'middle' or 'midway', while 半分 is the everyday word for 'half'.
Compound of 半 (half) and 分 (part, portion). The reading はんぶん is a straightforward on'yomi combination.