なけいようし・めいしの ふつうけい
な-adjectives & nouns, plain — meet だ & だった
あしたは やすみだ！
“Tomorrow's a day off!”
Step 1
Meet だ and だった (the copula, plain)「だ」と「だった」
な-adjectives and nouns use the copula です／でした／じゃありません／じゃありませんでした (Unit 23). In the plain form, two new shapes appear: だ (= です) and だった (= でした). The negatives just shorten patterns you already know.
ていねいpolite
ふつうplain
つくり方polite → plain
Present / futureaffirmative
だ= です の ふつうけい★ NEW
Present / futurenegative
じゃないshorten じゃありません✓ pattern
Pastaffirmative
だった= でした の ふつうけい★ NEW
Pastnegative
じゃなかったない → なかった✓ Unit 24
Nouns too!Nouns conjugate exactly the same way — just stick the same endings on a noun like がくせい (student).
Here are more な-adjectives and nouns in all four plain forms. 🔊 Tap any form to hear it.
な-adjpresentneg.pastpast neg.
pretty / clean
quiet
famous
convenient
healthy / energetic
kind
free (not busy)
liked / favorite
nounspresentneg.pastpast neg.
student
teacher
day off
friend
Step 2
Practice: です → the 4 plain formsフォームの れんしゅう
See the ていねい (です) form. Say the four plain forms in your head — remember だ and だった are the new ones — then tap to check.
Card 1 / 12
ていねい · な-adjきれいですpretty / cleantap to reveal the 4 plain forms
Step 3
Quiz: pick the right plain formクイズ
Read the sentence and the English, then choose the correct plain form.
Question 1 / 6 · 0 correct
fill the blankここは ◯◯。This place isn't quiet.
You've got all the plain shapes! Next: putting them together — when to use polite vs casual.