Why do we use は rather than に in インタネットがとても遅い時は、切腹したいです?


Why do we use は rather than に in the following sentence?

> インタネットがとても遅い時は、切腹したいです。

In my opinion it should be

> インタネットがとても遅い時に切腹したいです。

Any comments are welcome.




Both formulations are valid, and very likely mean the same thing.

"したいです" very unambiguously refers to the speaker, as if the subject was
someone else, it would be more appropriate to say "したいそうです" or "したいらしいです" (or
even "したいですと".)

The greatest difference of these two sentences is the context where it would
be appropriate to use. It would be more appropriate to use the second
formulation if [it was an answer to a specific
question](https://japanese.stackexchange.com/questions/24640/why-do-we-
use-%E3%81%AF-rather-than-%E3%81%AB-
in-%E3%82%A4%E3%83%B3%E3%82%BF%E3%83%8D%E3%83%83%E3%83%88%E3%81%8C%E3%81%A8%E3%81%A6%E3%82%82%E9%81%85%E3%81%84%E6%99%82%E3%81%AF-%E5%88%87%E8%85%B9%E3%81%97%E3%81%9F%E3%81%84%E3%81%A7%E3%81%99#comment53684_24640).

> **A:** どのタイミングで[ACTION]したいですか。
>
> **B:** インタネットがとても遅い時に[ACTION]したいです。

or perhaps more naturally:

> **A:** どのタイミングで[ACTION]したいですか。
>
> **B:** インタネットがとても遅い時(です)。

Using the first formulation (インタネットがとても遅い時 **は** ) is less appropriate when
the topic already has been established by the questioner. It might sound like
you aren't listening.

