〜と同時に: 'At the Same Time As...' (Meaning + Examples)
Two things lining up in time
〜と同時に marks that a second event happens right alongside, or immediately upon, a first one. With momentary verbs (鳴る, 卒業する, 聞く), it reads like "as soon as / the instant that."
ベルが鳴ると同時に、生徒たちが教室を出た。
べるが なると どうじに、せいとたちが きょうしつを でた。
The moment the bell rang, the students left the classroom.
鳴る (dictionary form) + と同時に — two events in an instant.
やったんは大学を卒業すると同時に、会社に就職した。
やったんは だいがくを そつぎょうすると どうじに、かいしゃに しゅうしょくした。
At the same time as graduating from university, Yattan got a job at a company.
Original example: two life events lining up.
もちはその知らせを聞くと同時に、泣き出した。
もちは その しらせを きくと どうじに、なきだした。
The instant Mochi heard the news, she burst into tears.
Form: plain verb / noun + と同時に
と同時に attaches to a verb's plain (dictionary) form for events, or directly to a noun for a dual-nature meaning ("both A and B at once").
| Attaches to | Pattern | Example |
|---|---|---|
| Verb (dictionary form) | Vる + と同時に | 卒業すると同時に (right as one graduates) |
| Noun | N + と同時に | 教師であると同時に (being a teacher, and also...) |
彼は学校の先生であると同時に、地域のボランティアリーダーでもある。
かれは がっこうの せんせいで あると どうじに、ちいきの ぼらんてぃありーだーでも ある。
He is a school teacher, and at the same time, also a local volunteer leader.
Noun-attached use: describing two roles held at once.
Sharper than 〜と、〜たら
Plain 〜と and 〜たら also link two clauses in sequence, but neither insists on simultaneity — they just show a general trigger-result relationship, possibly with a gap in time. と同時に is specifically for events that occur essentially together, at the same moment, which is why it fits "the bell rang and the students left right then" far better than a looser conditional would.
The short version
- Vる/N + と同時に = "at the same time as..." / "as soon as..." — two events occurring essentially together.
- Attaches to: a verb's dictionary form, or a noun.
- Nuance/register: neutral-to-formal; emphasizes near-simultaneity, often reading as "the instant that."
- Don't confuse with: plain 〜と or 〜たら, which link events in sequence without insisting they're simultaneous.
Practice it
Choose と同時に when two events happen essentially at the same moment.
＿＿＿に入れるのに最もよいものを選びなさい。
ベルが鳴る＿＿＿、生徒たちが教室を出た。
Where 〜と同時に fits
Shaky on this? Get these solid first
- 〜について · N3 — 〜について marks the topic you talk, think, or write about: 日本の文化について話す. Learn the form, the についての + noun pattern, についても, and how it differs from に関して.
More N2 grammar to explore
Keep going with related patterns at the same level:
- 〜ところだった — 〜ところだった means something almost happened but was narrowly avoided — 'I was just about to / I almost did.' It attaches to the dictionary form of a verb and often follows a close call like あぶない or もう少しで.
- つい — つい is an adverb meaning 'unintentionally / before I knew it' — it describes an action that slipped out despite the speaker's intentions, or a habitual slip. Common with speaking, eating, and other hard-to-control impulses.
- 〜は別として — 〜は別として means 'setting X aside' or 'apart from X' — it brackets off one topic as a separate matter so the speaker can address something more pressing, without denying the bracketed topic's importance.
- 〜はもとより — 〜はもとより means 'not to mention X, Y too' — it names an obviously-true first case and then emphasizes that an even more surprising or extended second case also holds, similar to 'let alone' but adding rather than negating.
- 〜はともかく — 〜はともかく means 'leaving X aside' or 'whether or not X' — it sets one topic apart as not the main point right now, so attention can shift to something more relevant, without judging the set-aside topic.
- わずかに — わずかに is an adverb meaning 'slightly,' 'a little,' or 'barely' — it emphasizes that an amount, degree, or difference is very small, often surprisingly so, and can modify verbs, numbers, or nouns of quantity.