Learn Hardcore Japanese: sorede, eki de koohii wo kaimasita.

Japanese often omits the subject when it’s clear from context. The sentence simply states the action: “(I) bought coffee at the station.” If you need to make the subject explicit, you can add 私は: 私は駅でコーヒーを買いました. Avoid overusing 私 in natural conversation.

Why is the particle で used after 駅? What’s the difference between で and に here?

Use で to mark the place where an action happens. Buying is an action done at a location, so 駅で is correct. に marks a point in time, existence, or a destination/arrival.

駅に着きました (arrived at the station) → destination/arrival
駅に人がいます (there are people at the station) → existence Not: × 駅にコーヒーを買いました.

Can I change the word order? For example, コーヒーを駅で買いました vs. 駅でコーヒーを買いました.

Yes. Particles carry the roles, so both are fine as long as the verb stays at the end.

駅でコーヒーを買いました (slight emphasis on where)
コーヒーを駅で買いました (slight emphasis on what) For stronger contrast/topic, use は: コーヒーは駅で買いました / 駅ではコーヒーを買いました.

What does それで do here? How is it different from だから, それから, そして, and それに?

それで links to the previous sentence as “so/and then,” often implying a result or continuation.

だから: “so/therefore,” stronger reason-result tone. 早く着いた。だから駅でコーヒーを買いました.
それから: “and then/after that” (sequence only, no causation). 電車を待った。それからコーヒーを買いました.
そして: simple “and,” often in writing for listing actions.
それに: “besides/moreover,” adds another point (not result). Also, それで？ alone means “And then?/So?” to prompt continuation.

Why is there a comma after それで? Is it required?

The comma 、 is optional but common after connectors like それで to show a natural pause. Writing それで駅でコーヒーを買いました without the comma is also fine.

Why is コーヒー written in katakana? Can I write it in kanji?

Loanwords are typically written in katakana, hence コーヒー. There is an old-fashioned ateji form 珈琲 that you might see on cafe signs, but it’s not common in everyday writing.

What does the particle を do? Can I drop it?

を marks the direct object (what is bought): コーヒーを. In casual speech it’s sometimes dropped when the meaning is obvious: 駅でコーヒー買った. Keep を in careful speech and writing.

What level of politeness is 買いました? How would I say it in plain form or other tenses?

買いました is the polite past of 買う (to buy).

Polite non-past: 買います
Polite past negative: 買いませんでした
Plain past: 買った
Plain non-past: 買う
Plain past negative: 買わなかった Use ます-forms in neutral/formal settings; use plain forms with friends/family.

Why ました and not でした?

ました attaches to verbs (買いました from 買う). でした is the past form of です and attaches to nouns/na-adjectives: 学生でした, 便利でした. Don’t combine ました with です.

Are spaces normal in Japanese sentences like this?

No. Standard Japanese doesn’t use spaces between words. The spaces here are for learners. Native-style: それで、駅でコーヒーを買いました。

Can I say 駅ではコーヒーを買いました? What does は add after で?

Yes. は adds a contrast/topic nuance. 駅ではコーヒーを買いました suggests “At the station (as opposed to somewhere else), I bought coffee,” or it sets “at the station” as the topic.

How would I say “I bought a coffee (one cup)”?

Use the counter 杯 for cups:

コーヒーを一杯買いました (I bought one cup of coffee).
一杯 is read いっぱい. For two and three: 二杯(にはい), 三杯(さんばい).
You can also say コーヒーを1カップ買いました, but 杯 is more natural for drinks.

If I want to stress that I bought it and brought it back with me, how do I say that?

Use 〜てくる: 駅でコーヒーを買ってきました. This means “I bought it (somewhere) and came (back) [with it],” often implying you now have it.

Could I replace それで with ので or から to express the reason?

ので and から are clause-level reason markers used within one sentence:

早く着いたので、駅でコーヒーを買いました.
早く着いたから、駅でコーヒーを買いました. それで links two clauses/sentences as “So/therefore” rather than embedding the reason.

Does で here ever mean “by/with,” like 電車で?

で can mark means (“by/with”) or location. In 駅で, it marks location (“at the station”). Context distinguishes:

電車で行きました (went by train) → means
駅で買いました (bought at the station) → location