Translation guide
To send out or release something such as light, heat, sound, gas, or radiation. Japanese uses different verbs depending on what is being emitted.
To give off light, warmth, or electromagnetic waves
General verb for emitting light, heat, or energy. Often used in written or formal contexts.
The sun emits light and heat.
Common for emitting light, sound, or signals. Slightly formal.
The lamp emits a soft light.
Everyday verb for putting out light, heat, or sound. Very common in casual speech.
The heater is emitting warm air.
To produce a sound, cry, or utterance
To release a gas, fume, or odor
Most common for emitting smoke, gas, or smells in everyday language.
The car is emitting exhaust fumes.
Formal or technical term for releasing substances into the environment.
The factory emitted hazardous substances.
Can be used for smells, but less common than 出す.
To release subatomic particles or electromagnetic radiation
出す is the most general and casual verb for emitting something. 発する is slightly more formal and often used for light, sound, or signals. 放つ implies a stronger, more forceful emission and is common in written or literary language.
English 'emit' is often translated directly as エミットする in technical contexts, but this is not natural Japanese. Use the verbs above depending on what is emitted.
He emitted a sigh.
サイレンが鋭い音を放った。
The siren emitted a sharp sound.
花が甘い香りを発している。
The flowers are emitting a sweet fragrance.