こと details
write + こと — turns a verb or a whole clause into an abstract noun
kaku koto
こと — turns a verb or a whole clause into an abstract noun
meaning: writing
人の話を最後まで聞くことが大事だよ。
hito no hanashi o saigo made kiku koto ga daiji da yo.
What matters is listening to people right to the end. casual
レポートは金曜日までに提出すること。
repooto wa kin'youbi made ni teishutsu suru koto.
Reports are to be submitted by Friday. formal
- dictionary form
- i-adjective
- na-adjective
- noun
Examples
the act or fact of doing, as an abstract noun — the pick for rules, definitions and anything stated rather than witnessed
人の話を最後まで聞くことが大事だよ。
hito no hanashi o saigo made kikukoto ga daiji da yo.
What matters is listening to people right to the end. casual
趣味は古い地図を集めることです。
shumi wa furui chizu o atsumeru koto desu.
My hobby is collecting old maps. neutral
当社の目標は、お客様に安心してお使いいただくことでございます。
tousha no mokuhyou wa, okyakusama ni anshin shite o tsukai itadaku koto de gozaimasu.
Our goal is for our customers to use it with peace of mind. formal
the written instruction — a bare こと ends a rule or a notice, with no copula or verb after it
レポートは金曜日までに提出すること。
repooto wa kin'youbi made ni teishutsu suru koto.
Reports are to be submitted by Friday. formal
Formation
{V}ことattaches to dictionary form{I}ことattaches to i-adjective{NA-stem}なことattaches to na-adjective{N}であることattaches to nounplain clause + こと（遅れたことを謝る・無理をしないことが大切だ）attaches to plain clause
Notes
noun (事の重大さ).
Related patterns
Similar
ということ hands the clause on as something said, heard or worked out, so it can be dropped in front of こと wherever the fact is reported (来ないということが分かった); bare こと takes the fact directly and is the shorter, plainer choice when the speaker vouches for it themselves.
Two nominalizers for one job, split by how the speaker knows the event — の is the spoken default and is the only option when the clause is seen, heard or interrupted in progress (見える・聞こえる・止める), while こと is the written pick and the only one the set frames ことができる／ことがある accept.
Lookalikes
言うことがある is two patterns at once — nominalizer plus がある is "there is something I have to say", while the set frame ことがある on a dictionary verb is "there are times when I say it"; only the context separates them, and the frame reading is the one a learner misses.
A notice ends 提出すること。 with the copula suppressed and no addressee in sight; ことだ names one and hands down advice (相談することだ) — the だ is the whole difference, and dropping it turns counsel into regulation.
Combines with
ことができる is this こと handed to できる, which needs a noun for its が-subject — の cannot stand in for it (×泳ぐのができる), which is why the frame is memorized whole.
ことにする／ことになる drop the nominalized action into the に slot of する／なる; の never appears in that slot, so 行くことにした has no 〜のにした counterpart.