How do you say “important” in Japanese?

たいせつ（な） - important (more of on a personal scale)

彼は私にたいせつな人です。

かれはわたしにたいせつなひとです。

He is an important person to me.

じゅうよう（な） - important (something big, something major)

彼はとても重要な人物です。

かれはとてもじゅうようなじんぶつです。

He is a very important man.

だいじ（な） - important (something of concern, something to be serious about)

時間を守ることは大事です。

じかんをまもることはだいじです。

It is important that you should be punctual.

Each are slightly different, so pick wisely...

Important People In Japan

For the best answers, search on this site shorturl.im/awKRt

First of all, in the Japanese language, these are not adjectival expressions but separate nouns. And this is semtical for every country. You take the country name and add "langauge" or "man" to it to make the word for the country's langueage and race. Japan is 日本 (Lit: Sun Origin) [read as nihon] The kanji for language is: 語 (read as go in this case) [the actual word for langauge is gengo: 言語] The kanji for person is: 人 (read as jin in this case) [it's read as hito normally] Such Japanese language is: 日本語 (nihongo) Japanese person is: 日本人 (nihonjin) Note that 日本 has an alternative reading, nippon, that could be used in every case. Nihon is considered the "official/primar" but both are more than correct. I speak Japanese: (私は)日本語を話せます。 (Watashi wa) nihongo wo hanasemasu. In English we use Present Simple, but Japanese would say it in potential form (can speak). You probably would omit the () part unless you are already talking about someone else. You could casually say: hanaseru (話せる) instead of hanasemasu "He's Japanese" 彼は日本人です。 Kare wa nihonjin desu. In this case, you could also omit "kare wa" if it is obvious from the context. And say it casually by changing desu to da: だ. Sidenote: You might hear ga (が) instead of wa. That is a fine replacement (Ga focuses more on the fact that it is you and not someone else) but it is more natural to say "wa" here. Sidenote2: You can use 日本 (nihon), 日本人 (nihonjin) and 日本語 (nihongo) as an adjective by adding a の (no) particle after it.

taisetsu (na-adj)

edit

and the moment i press submit button, this YuGiOh OP song i was listening to sang the word "taisetsuna".

"hontou ni taisetsuna koto nani ka na?"

juudai and daiji are also important.

There are also other ways of saying important in general:

juuyou, daiji and juudai

大切　（たいせつ）な

Taisetsu na

これは私に大切なことですよ。

Korewa watashini taisetuna kotodesuyo.

This is an important thing to me.

daiji na

ex.: daiji na mono. = important things.

juuyou na

ex.: juuyou na jinbutsu. = v.i.p. important person.

http://nihongodict.com/query.php?e=important