According to Essential Japanese Grammar by Masahiro Tanimori and Eriko Sato (page 352), we can pair adjectives in the ta-form with 時 to form a temporal adverbial clause. Strangely, the book doesn't provide an example using an adjective in the ta-form, only when it's in its dictionary form.


Book 時 section from page 351 to 353:

From Complete Japanese Grammar (page 156) by Eriko Sato, we only have:


If 嬉しいとき、悲しいとき、楽しいとき、怒ったとき、私はいつも泣きました。 translates into When I was happy, sad, delighted, angry, I always cried., why bother to conjugate each adjective into its ta-form?

While browsing the internet for answers, I have come across the following:

The tense of adjective sentences and noun sentences which modify とき is not affected by the tense of the main sentence.

Recovered from Learn Japanese Adventure

Other sites such as JLPT先生 only seem to consider the construction: い-adjective + とき

I can't think of a situation where an adjective in the ta-form has a role in the temporality of the sentence.

  • The Google Books version of that publication has no page numbers, and your link only goes to the front cover. I cannot find any specific place in the book where the authors claim anything about [ADJ]かった時 as a construction. Could you quote the instructional paragraph(s) that you are struggling with? Commented Sep 8, 2021 at 5:58
  • @EiríkrÚtlendi Would you mind a picture? I'll reduce the size of course.
    – Nameless
    Commented Sep 8, 2021 at 6:01
  • 1
    @EiríkrÚtlendi I've posted it. I took me a bit. If it's not clear, I would be pleased to take some photos again.
    – Nameless
    Commented Sep 8, 2021 at 6:11
  • 1
    Maybe upload the image to imgur or some other place and just write the URL?
    – Skye-AT
    Commented Sep 8, 2021 at 8:38
  • 3
    One minor thing is you shouldn't trust JLPTsensei. That site is highly misleading and contains numerous grammar errors. Please see this meta post.
    – Eddie Kal
    Commented Sep 8, 2021 at 17:04

3 Answers 3


The following is my intuition.

The pattern is Aとき, B, where A is an adjective.

(1) If you mean Whenever A, B, then both A and B are in dictionary form.

  • 暑い時はビールがおいしい Whenever it is hot, beer tastes good.

In this case 暑かったとき is not possible.

(2) If you mean an event in the past as When A, B happened, then B is in ta-form and A can be either in ta-form or in dictionary form.

  • 若い時アメリカに行った
  • 若かった時アメリカに行った

There may be subtle difference, but they both mean When I was young, I went to US. (The latter sounds suggesting more strongly that the speaker is no longer young.)

FYI Note if A is a verb, then there is a distinct difference depending on ta- or dictionary form of A in the second case. (or so it seems to me).

  • 本屋に行くとお金を使いすぎてしまう Whenever I go to a bookstore, I spend too much money.

As for a past event,

  • 本屋に行ったときXさんに会った When I went to a bookstore, I met X.
  • 本屋に行くときXさんに会った When I was about to go (or was on the way) to a bookstore , I met X.

Here た indicates an aspect of completion. Because of this difference, one or the other may be more suitable depending on what B describes.


AFAIK, there is no real difference between adjectives and verbs in terms of when to use their past-tense or non-past forms with 時. Both forms are valid and useful, but they do not mean the same thing.

I think the trick here is to understand that there's nothing really special (grammatically) about the 時 constructs: 時 is just a noun, which means "(a/the) time(s)". If you put a verb/adjective/clause/etc in front of it, that just modifies the noun 時 to be more specific about which time(s) (i.e. the specific point(s) in time) you are referring to, so you can just think of this general construct as saying "the time(s) when (verb/adjective/etc is/was/will be true)". So:

  • 暑いとき -- "the time(s) when (it) is hot" --> "at hot times", etc.

When the modifying clause is in the past tense, that actually says that at the point in time we are talking about, that action/event/condition/etc had already happened, so:

  • 暑かったとき -- "the time(s) when (it) had been hot (previously)"

On page 353 of your book, there is actually an example (with する instead of an adjective) which demonstrates this fairly well, I think:


This actually uses 時 twice, and if you'll note, one of them is using non-past tense (食事をする時), but the other is using past tense (した時). Why? Because in the first case, it is saying "at time(s) when we will (are about to) eat" (at the time we're talking about, the action hasn't happened yet, hence present/future tense), and the second one is saying "at time(s) when we have eaten" (at the time we're talking about, the action has already been completed, hence past tense).

As you might be able to guess, talking about "the time after some adjective had previously been true" isn't usually as common a sort of thing to be trying to say (compared to saying "the time after some event happened", etc), which is why the past-tense form with 時 isn't used as often with adjectives as with verbs, I think. However, the intrinsic meaning is still basically the same in both cases. It just depends on whether we're saying the adjective/verb is/was the case at that specific time, or it had been the case previous to that time.

  • How would, for example, 暑いとき、水を飲んだ differ from 暑かったとき、水を飲んだ?
    – Nameless
    Commented Sep 8, 2021 at 23:01
  • 「暑いとき、水を飲んだ」says "at times when it was hot, (I) drank water" (I am drinking water while I am in the heat). 「暑かったとき、水を飲んだ」says basically "at times after it had been hot, I drank water" (by the time I'm drinking, it may not be hot anymore, it's just that it had been hot previously (perhaps earlier in the day, etc)).
    – Foogod
    Commented Sep 8, 2021 at 23:18
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    @Nameless: 暑かった時 doesn’t mean “after it had been hot”. When you drank water, it was still hot. The difference from 暑い時 is that it is seen as a one-time, past event which is no longer the case, rather than a recurring condition. It sounds almost as if it will never be hot like that. So, you don’t usually use an adjective like 暑い in the ta-form before 時. See the examples with 若い in @sundowner’s answer.
    – aguijonazo
    Commented Sep 9, 2021 at 14:26

Doing some research, I've gathered the following:

When the predicate in an adverbial clause is stative in nature, its form does not change, regardless of the form in the main clause.


 "I wear a coat when it's cold."


 "I wore a coat when it was cold."

Japanese Stage-Step Course: Grammar Textbook: Grammar-Reference by Wako Tawa

In some cases (mostly with stative predicates and adjectives), however, -ta in toki clauses can simply indicate past time, just as in English.

(f) 日本に住んでいる時は、毎日日本語を使いました。

Nihon ni sunde iru toki wa, mainichi Nihongo wo tsukaimashita.

 When I lived in japan, I used Japanese every day.

(g) 日本に住んでいた時は、毎日日本語を使いました。

Nihon ni sunde iru toki wa, mainichi Nihongo wo tsukaimashita.

 When I lived in japan, I used Japanese every day.

Modern Japanese Grammar: A Practical Guide by M. Endo Hudson and Fumiko Nazikian

It is not necessary to use the past tense when pairing 時 with nouns, adjectives, and verbal expressions which express a state such as ある, いる, ~ている, or ~ない.

Nakama 2, Enhanced by Yukiko Abe Hatasa, Kazumi Hatasa and Seiichi Makino

  • If any misspelling or omission, please notify me.
    – Nameless
    Commented Sep 9, 2021 at 19:10

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