Learn Hardcore Japanese: asatte ha ame desu kara, kouen de hasirimasen. - It will rain the day after tomorrow, so I will not run in the park.

The particle は marks 明後日 as the topic of the sentence, indicating “As for the day after tomorrow….” By using は, the speaker sets 明後日 apart as the time frame they are commenting on. If you used が, it would simply identify 明後日 as the subject, which feels less natural here when you want to talk about conditions on that day.

Why is there no particle between 雨 and です?

When a noun (like 雨) directly becomes the predicate of a sentence, you don’t need an extra particle. The copula です attaches right after the noun to form “It is rain” (i.e. “It’s going to rain”). If you added a particle such as が, it would change the nuance (“Rain exists” rather than “It will rain”).

What role does から play in 雨ですから?

から means “because” or “since.” Attaching it after 雨です turns the statement “It will rain” into a reason clause: “Because it will rain….” It connects the first clause to the conclusion in the second clause (not running in the park).

Could I use ので instead of から? What’s the difference?

Yes, you could say 雨ですので. Both から and ので mean “because,” but there’s a slight nuance:

から is more direct and common in casual speech.
ので is slightly more formal or softer in tone, often used in written or polite contexts.

Why is で used after 公園? Couldn’t I use に?

The particle で indicates the location where an action takes place, so 公園で走りません means “not run in/at the park.” If you used に, it would mark 公園 as a point of arrival or existence (e.g. “go to the park” = 公園に行きます), not the location of the running itself.

Why is the verb 走りません in the negative non-past form? Does it refer to the future?

Japanese uses the non-past form (affirmative or negative) to talk about both present and future actions. Here, 走りません literally means “won’t run” (negative non-past) because of the context set by 明後日は雨ですから. There’s no separate future tense; the non-past negative covers it.

There’s no explicit subject like “I” or “we.” How do I know who won’t run?

Japanese often omits the subject when it’s clear from context. In many everyday sentences, the speaker implies “I” (or sometimes “we” if speaking for a group). Here, it’s understood that the speaker (or their group) won’t run in the park.

Can I drop です in 雨ですから to say 雨だから?

Yes. In casual speech, you can say 雨だから、公園で走りません. Dropping です makes it more informal. In polite contexts (like talking to strangers or in a business setting), you keep ですから to maintain politeness.