watashi wa ookina kouen de inu to issho ni sanposhimasu.

topic particle

Breakdown of watashi wa ookina kouen de inu to issho ni sanposhimasu.

• 犬いぬ: dog
• 私わたし: I
• と: companion particle

Questions & Answers about watashi wa ookina kouen de inu to issho ni sanposhimasu.

What is the function of は after 私, and why isn’t が used here?

は is the topic marker.

• 私 は = As for me / Talking about me…
• It sets 私 as the thing we’re talking about, and then the rest of the sentence explains something about that topic.

が is the subject marker, used when:

• introducing something new,
• emphasizing who did the action,
• or in certain fixed patterns.

In a simple, neutral sentence like this—“I walk with my dog in a big park”—Japanese usually uses は to present “I” as the topic of the sentence.
Using 私が大きな公園で…散歩します would feel like you’re emphasizing “I (and not someone else) am the one who walks,” which is not needed here.

Is 私 necessary here, or can it be omitted in natural Japanese?

私 can absolutely be omitted, and often is in natural Japanese.

You could say:

• （私 は）大きな公園で犬と一緒に散歩します。

Because the subject (“I”) is usually clear from context, Japanese speakers often leave 私 out unless:

• it’s needed to avoid ambiguity, or
• they specifically want to emphasize “I”.

So in everyday conversation, 大きな公園で犬と一緒に散歩します would sound perfectly natural as “I take walks with my dog in a big park.”

What’s the difference between 大きな公園 and 大きい公園? Are both correct?