Explanation
Expresses advice or recommendation; 'should', 'it is important', 'it is necessary'.
Formation
Verb-ますstem + ことだ, い-Adjective + ことだ, な-Adjective + なことだ, Noun + のことだ
Detailed explanation
The ～ことだ grammar point is used to express a piece of advice or recommendation to someone. It can be translated as 'should', 'it is important', or 'it is necessary' in English. The formation differs depending on whether it is used with a verb, い-adjective, な-adjective, or noun.
Examples
Mainichi undou suru koto da.
You should exercise every day.
Kenkou no tame ni, yasai wo takusan taberu koto da.
For your health, you should eat lots of vegetables.
Benkyou shiteiru toki, shizuka na basho wo erabu koto da.
When studying, you should choose a quiet place.
Jisho wo tsukatte, atarashii kotoba wo oboeru koto da.
You should use a dictionary to learn new words.
Practice
Grammar content sourced from hanabira.org.