こと

こと
noun
thing (abstract), matter
1. thing, matter, affair (abstract)
Refers to abstract concepts, events, facts, or situations. Unlike 物 (もの), which is for concrete objects.
I forgot something important.
I know about that matter.
Abstract 'matter' or 'thing'
Please don't tell this to anyone.
Please think about your health.
I often remember things from my childhood.
2. (nominalizer)
Turns verbs and adjectives into noun phrases, allowing them to be the subject or object of a sentence.
I can speak Japanese.
Nominalizing function with できる
I like swimming.
Nominalizing function - 'the act of swimming'
Have you ever been to Japan?
ことがある = to have the experience of
I decided to go to bed early.
Reading books is my hobby.
Keeping promises is important.

こと has two main uses: 1) As a noun meaning 'thing/matter/affair' for abstract concepts (compare with もの for concrete things). 2) As a nominalizer that turns verbs into noun phrases. The kanji (こと) is sometimes used.

Common patterns:

  • ことがある (to have the experience of)
  • ことができる (to be able to)
  • ことにする (to decide to).