Translation guide
Expressing that two or more actions or events happen at the same time.
Describing two actions that occur simultaneously, often with a focus on the overlap in time.
Used to express doing two actions at the same time. The main action is the second verb, and the subordinate action is the verb in the ながら form. Both actions are performed by the same subject.
音楽を聴きながら勉強する。
I study while listening to music.
I talked on the phone while walking.
Means 'at the same time as'. It can be used when two events occur simultaneously, and the subjects can be different. Often used in more formal or written contexts.
彼が到着すると同時に会議が始まった。
The meeting started at the same time as he arrived.
地震と同時に火災が発生した。
A fire broke out simultaneously with the earthquake.
Indicates that an action takes place during a period of time when another state or action is ongoing. The verb before 間 is in the dictionary form or ている form.
子供が寝ている間に本を読んだ。
I read a book while the child was sleeping.
夏休みの間に日本語を勉強するつもりだ。
I plan to study Japanese during summer vacation.
Similar to ながら, but more formal and literary. Used mainly in written language. The verb stem + つつ indicates a simultaneous action.
彼は成功を夢見つつ努力を続けた。
He continued his efforts while dreaming of success.
Emphasizing that two events happen exactly at the same moment, often with a sense of coincidence or synchronization.
Means 'the moment something happened'. It emphasizes the exact timing of the second event right after the first, but often implies near-simultaneity.
ドアを開けた瞬間に猫が飛び出した。
The moment I opened the door, the cat jumped out.
As above, but here it stresses the exact simultaneity of two events. Can be used with nouns or verbs.
スタートの合図と同時に走り出した。
They started running at the exact same time as the starting signal.
A literary expression meaning 'as soon as' or 'the moment'. It implies that the second action happens immediately after the first, almost simultaneously. Used in written language.
彼は家に着くや否や、雨が降り出した。
The moment he arrived home, it started raining.
Describing two states or conditions that exist at the same time, without focusing on actions.
Used to connect two states or qualities that coexist. Often used with adjectives or nouns.
この車は速いと同時に安全だ。
This car is fast and, at the same time, safe.
Means 'while being' or 'although'. It expresses that two seemingly contradictory states exist simultaneously. More emphatic than ながら.
彼は学生でありながら、会社を経営している。
While being a student, he runs a company.
Referring specifically to the act of interpreting spoken language in real time.
The standard term for simultaneous interpretation. Often used in professional contexts.
会議では同時通訳が提供された。
Simultaneous interpretation was provided at the conference.
The verb form meaning 'to do simultaneous interpretation'.
彼女は英語と日本語の同時通訳をする。
She does simultaneous interpretation between English and Japanese.
ながら is used when the same person does two actions at the same time. 間に is used when an action takes place during a time period defined by another action or state, and the subjects can be different.
私は音楽を聴きながら勉強する。
I study while listening to music. (same subject)
私が勉強している間に、彼はゲームをしていた。
While I was studying, he was playing games. (different subjects)
The English word 'simultaneous' is often translated as 同時の, but in natural Japanese, it's more common to use patterns like 〜ながら or 〜と同時に to express simultaneous actions. Using 同時の as a direct adjective can sound unnatural in many contexts.
二つの出来事が同時に起こった。
The two events happened simultaneously.
彼女は勉強しながら音楽を聴くことができる。
She can study and listen to music simultaneously.