Translation guide
How to express that something is one of a pair in Japanese, depending on what is being counted and the context.
Referring to a single item that is part of a set of two identical or complementary objects.
Means 'one of a pair' or 'one side'. Used for items that come in twos, like shoes, socks, gloves, earrings, etc. Often used with the counter 〜の.
I can't find one of my shoes.
I lost one of my gloves.
Casual, colloquial version of 片方. Common in everyday speech.
One of my socks went somewhere.
Literally 'one fragment', can mean one of a pair, but often implies a broken or separated part. Less common for everyday items.
I'm looking for the other half of my earring.
Referring to one member of a pair of people or entities that are associated.
Also used for people in a pair, like a couple or partners.
One of the couple is Japanese.
Means 'one side' or 'one of the two'. Often used in contrasts or when discussing two options/parties.
Simply 'one person'. Use when the pair is understood from context.
Referring to one side of something that has two symmetrical halves.
Works for body parts like eyes, ears, hands, etc.
I can't see out of one eye.
Prefix meaning 'one of a pair' attached to body parts or objects. E.g., 片目 (one eye), 片耳 (one ear), 片手 (one hand).
He drives with one hand.
片方 (かたほう) is used for one of a pair of concrete items or people that are a set. 一方 (いっぽう) is more abstract, often used for one of two alternatives, directions, or contrasting situations. For physical pairs, 片方 is more natural.
One side of the road is closed.
Do not translate 'one of a pair' word-for-word as ペアの一つ or similar. Use 片方 or context-appropriate counters.
双子の一方は医者になった。
One of the twins became a doctor.
One of the pair was absent.
片耳が聞こえない。
I can't hear out of one ear.