Why are we using で instead of を here?

[Atani]

Hey everyone,

I was just looking at the example sentences of the ましょうか section.
One of the sentences is:

日本語で話しましょうか
Shall we speak in Japanese?

I was wondering why the で-particle is used in this case?
I would’ve said 日本語を話しましょうか

For me this is the same as in 日本語を勉強しています (I am studying Japanese).

Could someone explain this to me please?

[mrnoone]

Hey

The particle で is not only used to mark locations but has another use (among others) - marking means of doing something (tools). Like “with” and “by” in English.

Examples:
getting to work by bus, cutting cake with a knife, speaking in English etc

So you could say it means something along:
“Shall we communicate by means of Japanese?”

https://bunpro.jp/grammar_points/36

By the way, を also does not only mark direct object (answers to question "who/what is being verbed - I am studying(verbing) Japanese), but also has another uses I superficially explained here:

を - Grammar Discussion

You are right, this is too much of a hint. I will change those to [choose proper particle.] Yes you are right. It is not a direct object use. The を in 出る is used to describe a starting point of the movement, similar to から. It is used with verbs like 発つ（たつ）、出る（でる）、離れる（はなれる）etc. But you focus only on that point of start, you don’t mention the goal of movement, you don’t know where(or don’t want to say it) or it is simply not important. This is the difference with から, which is used for the m…

[Atani]

Thanks a lot!

By looking at the grammar point you linked to, I saw that this use of で is explained later in Genki - I’m just not that far into the book There is even the same example mentioned.