Translation guide
The English verb "copulate" refers to the act of sexual intercourse, typically in a biological or formal context. In Japanese, the most common and neutral way to express this is 交尾する (for animals) or 性交する (for humans). However, in everyday conversation, more indirect or euphemistic expressions are often preferred.
To describe animals mating in a scientific or formal context.
The standard term for animal copulation. Used in biology, zoology, and formal writing.
その昆虫は春に交尾する。
The insects copulate in spring.
A more technical term for copulation, often used in scientific contexts for invertebrates or specific biological descriptions.
甲殻類の交接行動を観察した。
We observed the copulatory behavior of crustaceans.
To refer to human sexual intercourse in a formal, medical, or legal context.
The standard formal term for human sexual intercourse. Used in medical, legal, and educational contexts.
法律上、同意のない性交は犯罪です。
Legally, non-consensual copulation is a crime.
Can also be used for humans in very formal or biological texts, but 性交する is more common.
人間の交接は複雑な心理的要素を含む。
Human copulation involves complex psychological factors.
To talk about having sex in a casual or indirect way, avoiding direct terms.
The most common and neutral loanword for 'have sex'. Widely understood and used in casual conversation.
彼らは昨夜セックスしたらしい。
Apparently they had sex last night.
A euphemistic and slightly childish term for having sex, derived from the letter 'H'. Very common in informal speech.
昨日彼女とエッチした。
I had sex with my girlfriend yesterday.
Literally 'to sleep', but often used euphemistically to mean 'sleep together' or 'have sex'. Context-dependent.
Can be ambiguous; clarify with context if necessary.
彼と寝たことはない。
I've never slept with him.
A very casual and somewhat vulgar slang term for 'do it' or 'have sex'. Used mainly among close friends or in rough speech.
Can sound crude; avoid in polite conversation.
昨日やった？
Did you do it yesterday?
To use explicit or crude terms for sexual intercourse.
Direct loanword from English 'fuck'. Considered very vulgar and offensive in most contexts.
Extremely offensive; avoid unless intentionally using strong language.
あの二人はファックしてる。
Those two are fucking.
Direct translations of 'copulate' like 交尾する or 性交する sound very formal and are rarely used in daily conversation. For casual talk, use セックスする or euphemisms like エッチする. Using formal terms in casual settings can sound awkward or overly clinical.
交尾する is specifically for animals. Using it for humans can be dehumanizing or humorous. For humans, use 性交する (formal) or セックスする (casual).