Learn Hardcore Japanese: kazi wo hayaku owaraseru kuhuu wo memo ni kaita. - I wrote down ideas for finishing housework quickly.

Japanese often omits the subject when it’s clear from context. Here it’s most naturally “I” (the speaker), but depending on context it could be “he/she/they.”

Why are there two を particles? Is that allowed?

Yes. The first を belongs to the relative clause 家事を早く終わらせる, and the second を is for the main verb 書いた. So it’s “[ways to finish chores quickly] (object) + wrote (on a memo).”

What exactly is the structure of 家事を早く終わらせる工夫?

It’s a relative clause modifying 工夫. Japanese relative clauses don’t require the head noun to be the subject of the clause; it means “tips/ways for finishing chores quickly.”

Why use 終わらせる instead of 終える or 終わる?

終わる = “to end” (intransitive).
終える = “to finish (something)” (transitive, a bit bookish/formal).
終わらせる = causative of 終わる, “to make [it] end / get [it] finished,” common and natural in conversation. Here 終わらせる feels like “get the chores done.”

Does the causative 終わらせる mean “make someone else finish”?

Not necessarily. Without a “causee” marked by に (e.g., 彼に家事を終わらせた), it typically means “I/we got it done.” In everyday Japanese, 終わらせる often just means “finish (something).”

What’s the difference between 早く and 速く here?

早く = “early/sooner,” focuses on finishing earlier in time. 速く = “fast/quickly,” focuses on speed of action. For chores, 早く is most natural if the goal is to finish sooner; 速く would emphasize doing the tasks at a faster pace.

Could I say 早めに終わらせる instead?

Yes. 早めに means “a bit earlier/sooner than usual,” slightly softer than 早く. It sounds like “try to get them done earlier (than you normally would).”

What does 工夫 mean, and how is it different from 方法／アイデア／コツ／考え?

工夫: clever tweaks/ingenuity/resourceful adjustments.
方法: method/procedure, neutral and general.
アイデア: idea (often creative or novel).
コツ: knack/trick for doing something well.
考え: thought/plan, broad and abstract.
Here 工夫 suggests “practical little tricks.”

Why メモに and not メモで or メモを?

With 書く, the target surface takes に: XをYに書く (“write X on Y”). メモで would mean “by/with a memo” (odd here), and メモを書く means “write a memo” (compose a memo), not “write on a memo.”

Is メモを取った or メモした okay here?

Yes. 工夫をメモした or 工夫をメモに取った both mean “jotted the tips down.” メモに書いた focuses on the act of writing on the memo; メモを取る／メモする is the general act of note-taking.

Can I change the word order to メモに工夫を書いた?

Yes. 工夫をメモに書いた and メモに工夫を書いた are both natural. Word order is flexible; placing メモに first slightly highlights where you wrote it.

Do I need ための (家事を早く終わらせるための工夫)?

Not required. Adding ための makes the purpose explicit and can feel a bit more formal or explanatory. Without it, it’s already understood as “tips to finish chores quickly.”

Is 書いた polite enough? What about 書きました?

書いた is plain past (casual or neutral narrative). Use 書きました in polite contexts. The rest of the sentence stays the same: 家事を早く終わらせる工夫をメモに書きました。

What does 書いておいた add?

書いておいた means “I wrote it down (in advance)/so it’ll be there when needed,” implying preparation or for future benefit. Very natural if that’s the nuance you want.

Is the spacing in the sample normal in Japanese?

No. Standard Japanese doesn’t use spaces between words. You would write: 家事を早く終わらせる工夫をメモに書いた。

Can I say メモを書いた instead of メモに書いた?

メモを書いた = “wrote a memo” (you composed a memo). メモに書いた = “wrote (something) on a memo.” In your sentence, you’re writing the 工夫 onto a memo, so メモに書いた fits better.

Are 終わす or 終わらす correct?

They’re casual/colloquial variants of 終わらせる. You’ll hear them in speech (e.g., 早く終わらす) but they’re less standard in writing.

If I want to stress finishing earlier vs doing the chores quickly, how can I say that?

Finishing earlier: できるだけ早く終わらせる, 早めに終わらせる.
Doing quickly (speed): 速く片付ける, てきぱき片付ける, さっさと終わらせる (colloquial).

Can I replace 家事 with 用事 or 宿題?

Yes, grammatically it works. 用事 = “errands/tasks” (often outside the home too), 宿題 = “homework.” The meaning shifts accordingly: “ways to finish errands/homework quickly.”