The copula だ (da)

The copula da behaves very much like a verb or an adjective regarding conjugation.

Stem forms of the copula-
Attributive form (連体形 rentaikei)である (de aru)
Terminal form (終止形 shūshikei)だ (da, informal)

です (desu, polite)

でございます (de gozaimasu, respectful)

Continuative form ((連用形 ren'youkei)で (de)
Imperfective form (未然形 mizenkei)では (de wa)
Hypothetical form (仮定形 kateikei)[/B]なら (nara)
Imperative form (命令形 meireikei)impossible

Note that there are no potential, causative, or passive forms of the copula, just as with adjectives. The following are some examples.

JON wa gakusei da
John is a student.

ashita mo hare nara, PIKUNIKU shiyō
If tomorrow is clear too, let’s have a picnic.

In continuative conjugations, では (de wa) is often contracted in the speech to じゃ(ja); for some kinds of informal speech ja is preferable to de wa, or is the only possibility.

Conjugations of the copula--
nonpastinformalだ (da)
-politeです (desu)
-respectfulでございます (de gozaimasu)
pastinformalcont. + あった (atta)

だった (datta)

-politeでした (deshita)
-respectfulでございました (de gozaimashita)
negative nonpastinformalcont. + はない (wa nai)
-politecont. + はありません (wa arimasen)
-respectfulcont. + はございません (wa gozaimasen)
negative pastinformalcont. + はなかった (nakatta)
-politecont. + はありませんでした (wa arimasen deshita)
-respectfulcont. + はございませんでした (wa gozaimasen deshita)
conditionalinformalhyp. + ば (ba)


cont. + あれば (areba)
provisionalinformalなら (nara)


same as conditional
volitionalinformalだろう (darō)
-politeでしょう (deshō)
-respectfulでございましょう (de gozaimashō)
adverbial and -te formsinformalcont.
-politecont. + ありまして (arimashite)
-respectfulcont. + ございまして (gozaimashite)

Japanese Grammar Contents

  • Part 1: Textual classifications; nouns, pronouns, and other deictics
  • Part 2: Conjugable words: verbs
  • Part 3: Conjugable words: adjectives
  • Part 4: Conjugable words: the copula だ da
  • Part 5: Euphonic changes, colloquial contractions
  • Part 6: Adverbs, sound symbolism, conjunctions and interjections
  • Part 7: Particles
  • Part 8: Auxiliary verbs