Practice JLPTHow to tell them apart
際（に） marks a formal, special occasion and sounds stiff in everyday speech, while 時・とき is the general word for any time or moment. Use 際（に） for ceremonies, important opportunities, or set phrases like この際; use 時・とき for routine events like 食べる時 or 寝る時. Swapping them feels odd: 卒業の際に is natural, but 朝ごはんを食べる際に sounds overly formal.
- 際（に） Use 際（に） for formal or special occasions like graduations, ceremonies, or important opportunities.
- 時・とき Use 時・とき for ordinary, everyday timing without any special or formal nuance.
際（に） ni
When/Occasion (formal)
When; on the occasion of; at the time of | On the special occasion of/when.
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この際、私が直接社長に話してみます。
Since this is an important occasion (literally: on this occasion), I will talk directly to the president (and see what happens).
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これは大学卒業の際に父が買ってくれたワープロです。
This is a word processor which my father bought me on the occasion of my college graduation.
時・とき toki
When / at the time of
At the time when; when | A dependent noun which indicates the time when someone/something will do/does/did something or the time when someone/something will be/is/was in some state.
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これは出発の時に渡します。
I'll give this to you at the time of your departure.
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ひろしは試験の時（に）風邪を引いた・引きました。
Hiroshi caught a cold at the exam time.
際（に） and 時・とき are JLPT N5–N3 grammar points that Japanese learners often mix up. This page compares them side by side — meanings, usage and example sentences — so you can tell them apart.