Is it not needed to use an adjective in the ta-form when paired with 時 as a temporal adverbial clause?


According to [Essential Japanese Grammar by Masahiro Tanimori and Eriko Sato
(page
352)](https://books.google.com.mx/books/about/Essential_Japanese_Grammar.html?id=CUXRAgAAQBAJ&printsec=frontcover&source=kp_read_button&hl=en&redir_esc=y),
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.

> 暑い時はビールがうまい.

Book 時 section from page 351 to 353:

  * [PAGE 351](https://imgurupload.org/files/Studio-20210908-010549.jpg)
  * [PAGE 352](https://imgurupload.org/files/Studio-20210908-012712.jpg)
  * [PAGE 353](https://imgurupload.org/files/Studio-20210908-010728.jpg)

From [Complete Japanese Grammar (page 156) by Eriko
Sato](https://rads.stackoverflow.com/amzn/click/com/B00JQJ1O88), we only have:

> 暑いときはエアコンをつけます。

* * *

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](https://www.learn-japanese-
adventure.com/toki-in-japanese.html)

Other sites such as [JLPT先生](https://jlptsensei.com/learn-japanese-
grammar/%E6%99%82-%E3%81%A8%E3%81%8D-toki-meaning/) 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 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.




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.

