和英辞書

だ

verb

to be / should; be obliged to; ought to / です follows i-adjectives, as the standard polite terminal form for i-adjectives.

これは私のペンだ。

This is my pen.

意味（1）

to be

彼(かれ)は無(む)実(じつ)だ。

Kare wa mujitsu da.He is innocent.

意味（2）

should; be obliged to; ought to

汚(お)物(ぶつ)は消(しょう)毒(どく)だ。

Obutsu wa shōdoku da.The filth should be disinfected.

意味（3）

です follows i-adjectives, as the standard polite terminal form for i-adjectives.

遅(おそ)いですね。

Osoi desu ne.You are too slow.

意味（4）

だろう / でしょう / なら can follow any inflectable word, forming suppletive volitional/polite volitional/conditional forms.

飲(の)むなら乗(の)るな！

Nomu nara noru na!If you are to drink, don't drive!

意味（5）

(auxiliary) Not following any words, but used before some conjunctives or in some inflected forms, to represent the aforementioned statement.

山(やま)をなめてはいけない。でないと死(し)んじゃうよ。

Yama o namete wa ikenai. De nai to shinjau yo.Don't underestimate the difficulty of mountaineering. If you do, you could die.