〜ことだ
JLPT N3:the thing to do is
Gives direct advice: "you should…", "the best thing is to…".
How to form it
- Put the verb in the dictionary form or the ない form and add ことだ: よく寝ることだ, 無理をしないことだ.
- A condition often comes first: 上手になりたいなら、毎日練習することだ (if you want to improve, practise every day).
Examples
健康のためには、よく寝ることだ。
For your health, the thing to do is get plenty of sleep.
上手になりたいなら、毎日練習することだ。
If you want to get better, practise every day.
Notes
- It is usually said by someone older or more experienced, and does not suit advice to a superior.
Common mistakes
- Confusing it with こと as a nominalizer. ことだ at the end of advice means "you should".
Similar meaning
- 〜べきshould
"Should": what is right, stated as a general principle.
- 〜たらいい / 〜ばいいshould / what should I do
"You should" as friendly, everyday advice.
- 〜ものだthat's how it is / used to
ものだ: what people naturally or properly do.