だ: To be, is

だ is an auxiliary verb in Japanese that acts as an expression of determination, or strong assertion. It simply states that something 'is' a certain way.

Structure

• Noun + だ
• [ な ] Adjective + だ

About だ

• だ marks nouns and な-adjectives as present tense and positive, but it can also add an emphatic nuance in some contexts.
• It is a casual equivalent of です
• だ should always be attached to the end of nouns, or words that can behave like nouns, such as な-Adjectives. (Except い).

Caution

• だ should never be attached to the end of い-Adjectives. In these cases, it is considered more correct to attach a polite equivalent, like です.
• While だ is often thought of as the casual 'form' of です, that is actually not correct. です is a polite speech word. The official 'formal version' of だ is である

Synonyms

• です (To be, is)
• でござる (To be, Polite copula)
• がある (To be, There is)
• である (Formal or literary だ)
• だった. でした (Was, Were (Past tense))

Antonyms

• じゃない (Is not, Isn't)

Examples

• 私だ - It's me.
• ほんだ - It's a book.
• ねこだ - It's a cat.
• がくせいだ - I'm a student.

References:

だ

だ marks nouns and な-adjectives as present tense and positive, but it can also add an emphatic nuance in some contexts.

Tofugu

だ (JLPT N5) | Bunpro – Japanese Grammar Explained

だ is an auxiliary verb in Japanese that acts as an expression of determination, or strong assertion. It simply states that something ‘is’ a certain way. It is a…

Bunpro – Japanese Grammar Explained

Outro

KURENAI だ！

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