Translation guide
The English word 'half' can refer to a 50% portion, a midpoint, or partial states. In Japanese, the most common equivalent is 半分 (はんぶん), but other expressions like 半 (はん) as a prefix, 半数 (はんすう) for 'half the number', and idiomatic phrases are used depending on context.
Expressing exactly one of two equal parts of something.
The most common and versatile word for 'half'. Can be used for physical objects, abstract quantities, time, etc.
Please cut the cake in half.
Attaches to nouns to mean 'half-', often in fixed compounds. Not freely productive.
Used specifically for 'half the number' of people or countable items.
Referring to the middle point of a period, distance, or process.
Describing something that is not fully realized or only partly done.
Used in compounds to mean 'semi-', 'partly', or 'half-'. Common in words like 半透明 (translucent) or 半信半疑 (half in doubt).
translucent glass (half-transparent)
Expressing 'half' in numerical or fractional contexts.
The standard fractional expression for 'one half'.
半分 means a 50% portion, not a midpoint in a journey or process. Use 途中 or 真ん中 for spatial/temporal midpoints.
半分 is for portions of a whole (mass, volume, abstract). 半数 is specifically for half of a countable number of people or things.
Half of the participants were women.
I only understood half of what he said.
Half of the work is done.
クラスの半数が賛成した。
Half the class agreed.
Means 'middle' or 'center', often used for spatial midpoints. Can imply 'halfway' in context.
Don't stop in the middle of the road.
Means 'on the way' or 'midway', often for processes or journeys.
I fell asleep halfway through the movie.
Literary or formal word for 'middle' or 'halfway', often used in temporal or abstract contexts.
I changed careers in the middle of my life.
半信半疑で話を聞いた。
I listened to the story half in doubt.
Means 'half-finished', 'half-hearted', or 'neither one thing nor the other'. Often negative.
Stop being so half-hearted.
The probability is one half.
Used after numbers to mean 'and a half'. E.g., 三時半 (3:30), 一か月半 (one and a half months).
Let's meet at half past three.
It took a month and a half.
I ate half of the cake.
We split the bill in half.
Natural Japanese uses 割り勘 (splitting evenly), not a literal 'half'.