時(とき)When, At the time of

とき, or 時(とき) in kanji, is a noun that is regularly used to signify 'when' something happened (a verb). However, unlike some other time expressions, とき is mainly used to express things that happen at regular intervals (habits, hobbies, etc.), or at broad times/individual events (when it rains, when there is a sale at the shop, etc.)

Using とき is quite easy! You just need to attach it to the end of any independent word (verbs, nouns, or adjectives). As with most cases where a noun will be attached to another word in Japanese, we will also be required to use な after な-Adjectives, and の after nouns. The case-marking particle に will generally come directly after 時(とき), signifying that another verb is about to follow.

Caution

As discussed previously, ときに is primarily used to discuss when things happened. What this means is that it will not be used to highlight ongoing states that were true during the first action. For example 'the time you tripped over a log on Tuesday'.

When とき is used, the nuance will be that it is describing one thing leading to another, rather than a static thing.