do so / do it / do that の使い分けDo So, Do It, Do That
代名詞 / Pronouns
3つとも「さっき出た行為」の代わりですが、距離と硬さが違います。do it は中立(その行為を)、do that は少し距離を置く(そんなこと)、do so は書き言葉の道具(行為をそのまま受け直す)。会話は it と that で回り、so は規則文や報告書で生きます。
All three stand in for an action already mentioned, but they differ in distance and dress. Do it is neutral: that act. Do that stands back a step: that kind of thing. Do so is written-register equipment for re-mentioning an action as it stands. Conversation runs on it and that; so earns its keep in rules and reports.
距離の it と that、書き言葉の so
Close It, Distant That, Written So
it と that の差は、代名詞の it と that の関係がそのまま持ち込まれています。it は手元で持ち続ける、that は距離を置いてつかむ。だから相手の行為には that が出やすく、Don't do that.(やめてよ)には軽い非難が乗ります。Why did you do that?(なんでそんなことしたの)も同じです。do so にはこの体温がありません。Employees may work remotely, and most choose to do so. のように、直前に出た行為を書き言葉で受け直すための装備です(主語は同じでなくても構いません)。会話で do so と言うと、ネクタイを締めて夕食に来たような響きになります。
The gap between it and that imports straight from the pronouns: it holds a thing close; that grips it at arm's length. So other people's actions attract that, and Don't do that carries a note of reproach, as does Why did you do that? Do so has no body heat at all. It re-mentions an action in writing: Employees may work remotely, and most choose to do so. The subject need not be the same one. Say do so at the kitchen table and you've arrived at dinner in a necktie.
3つの体温Three temperatures
"Can you send me theなぜ the なのか【その場で一つに決まる】話し手と聞き手のいる状況で、どれを指すか一つに決まるから the。日本語なら「（例の）」「うちの」を補って読むと感覚が近い。 file?" "I'll do it right now."
「ファイル送ってくれる?」「今すぐやるね」
自分が引き受ける行為は it。Your own accepted task takes it.
Stop doing that. It's really annoying.
それ、やめてってば。ほんとに気に障る。
相手の行為への that。非難が乗る。That for someone else's act, reproach included.
Visitors must sign in; anyone failing to do so will beこの文の組み立て【未来の受動】will be ＋ 過去分詞で、これから「〜される」。受動に未来が重なった形。turned away.
来訪者は記帳をお願いします。記帳のない方は入場をお断りします。
規則文の do so。ここが生息地。Do so in its native habitat: rules.
do it / do that(会話)
it =手元の行為、that =距離を置いた行為。日常はこの2つで足りる。It for the act in hand, that for the act at arm's length — daily life needs no more.
"Someone should call the landlord." "I'll do it."
「誰か大家さんに電話しないと」「私がやるよ」
do so(書き言葉)
行為の受け直し。規則・報告・論文の道具。An action, re-mentioned — the tool of rules, reports, papers.
Those who wish to cancel may do so at any time.
解約を希望する方は、いつでも解約できます。
よくある間違い / Common Mistake
×"Did you back up the files?" "Yes, I did so this morning."
「ファイルのバックアップした?」「うん、今朝やったよ」(のつもりで)
○"Did you back up the files?" "Yes, I did it this morning."
「ファイルのバックアップした?」「うん、今朝やったよ」
do so は書き言葉の装備なので、会話に持ち込むと不自然に儀礼的な響きになります。日常の返事は did it、もっと軽くは助動詞で止める Yes, I did. だけでも十分です(省略の項)。もうひとつ、do so には中身の制限があります。受けられるのは「行為」だけで、状態は受けられません。He owns three cars, and his brother does so too. は不可で、does too に替えます。it と that にはこの心配は実用上ありません。
Do so is written equipment; carried into conversation it sounds stiffly ceremonious. The everyday reply is did it, or lighter still, just Yes, I did (see the ellipsis entry). Do so also restricts its cargo: it carries actions only, never states. He owns three cars, and his brother does so too fails; make it does too. It and that impose no limit worth worrying about in speech.
I'll do it.私がやるよ。引き受けの定番。手元に取る it。The volunteering line, it taking the task in hand.
Don't do that.やめて。相手の行為に距離を置く that。軽い非難込み。That at arm's length, reproach included.
do so at your own risk自己責任で行ってください規約文の定型。do so の生息地そのもの。Terms-and-conditions grammar: do so at home.
You did it!やったね!達成の祝福。責める You did this. と混同しない。The congratulation — not the accusing You did this.
まとめ / Summary
do it =中立、do that =距離(非難が乗りうる)、do so =書き言葉。Do it is neutral; do that keeps distance; do so is written register.
会話は it と that で足りる。do so は規則・報告で。Conversation runs on it and that; do so lives in rules and reports.
do so が受けられるのは行為だけ。状態は does too へ。Do so carries actions only; for states, switch to does too.
もっと軽く受けるなら、助動詞で止める(Yes, I did.)。Lighter still, stop at the auxiliary: Yes, I did.