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> 道を渡るとき、車に気をつけてください

Is there an implicit は being dropped after とき? Or is/can とき function
adverbially (so that no particle need be after it, at least not necessarily)?
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2023-06-22T00:59:32.337
100030
2023-06-26T01:07:08.443
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question
adverbs
Can とき function adverbially?
There is an implicit に dropped after とき. The complete way of saying it should
be "道を渡るとき **に** ", meaning " **at** the time of crossing roads." とき is a
noun, Vとき(V being a verb) means "the time of doing V", which is a noun phrase.
You need the particle に (here it should translate to "at") to make this an
adverbial phrase: Vときに ( _ **at**_ the time of doing V). This particle, as you
see here, is often dropped.

You could also argue that we put a は there, but then the focus of the sentence
would shift to "道を渡るとき", giving it emphasis, making it the topic of the
sentence. With how the sentence is written right now, I'd say it's pretty
"neutral", no special emphasis given to the part "道を渡るとき".
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2023-06-22T01:07:37.297
100031
2023-06-22T01:07:37.297
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answer
> Can とき function adverbially?  
>  Or is/can とき function adverbially (so that no particle need be after it, at
> least not necessarily)?

Yes, it can. No particle necessarily need to be after it **in your sentence**.
(「～ときに...」 has different nuance from 「～とき...」)

An example sentence from
[デジタル大辞泉](https://dictionary.goo.ne.jp/word/%E3%81%A8%E3%81%8D/#jn-157586):

> とき【時】  
>  10 （行為や状態を表す連体修飾を受けて）  
>  ㋐ある状態になっている時点や時期。「家に着いた **とき** 、母はいなかった」

* * *

> 道を渡るとき、車に気をつけてください。  
>  道を渡るときは、車に気をつけてください。

Both above sound good to me, but

> 道を渡るときに、車に気をつけてください。

doesn't sound natural.

[～ときに + imperative] can be used in a case like this:

> 時間があるときに来てください。(← talking about _when_ one should visit.)  
>  今度来たときに提出してください。(← talking about _when_ one should submit, e.g. as a
> response to "When should I submit this?")  
>  (時間があるとき来てください、今度来たとき提出してください would also be acceptable)
>
> Compare: 道を渡るとき(は)、車に気をつけてください。(← not talking about when one should be
> careful, but talking about what one should do when crossing a road.)
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2023-06-26T01:07:08.443
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2023-06-26T01:07:08.443
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answer