Kanji Library
AdjectivesJLPT N1

ややこしい (yayakoshii) conjugation

JLPT N1 i-adjective (形容詞)

puzzling, tangled, complicated, complex

ややこしい (ややこしい, yayakoshii) is an i-adjective. I-adjectives carry their own tense: drop the final い and the endings attach straight to the stem. No だ, no です needed to make a complete sentence.

Conjugation table

FormPlain (casual)Polite (~です)When you use it
Dictionary / plain
yayakoshii

yayakoshiidesu
The form you look up. Also the casual “is ~”.
Negative
yayakoshikunai

yayakoshikunaidesu
“is not ~”.
Past
yayakoshikatta

yayakoshikattadesu
“was ~”.
Past negative
yayakoshikunakatta

yayakoshikunakattadesu
“was not ~”.
Te-form
yayakoshikute
Links to the next clause: “~ and …”.
Adverb
yayakoshiku
Turns it into “~ly”, describing a verb.
Before a noun
yayakoshii〜
How it attaches when it modifies a noun.
Conditional (~ば/なら)
yayakoshikereba
“if it is ~”.
Conditional (~たら)
yayakoshikattara
“if / when it is ~”. The everyday conditional.
Become (~なる)
yayakoshikunaru

yayakoshikunarimasu
“becomes ~” — the change-of-state form.
Too much (~すぎる)
yayakoshisugiru

yayakoshisugimasu
“too ~”.
Looks ~ (~そう)
yayakoshisou

yayakoshisoudesu
“looks / seems ~” from appearance.

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Why it conjugates this way

I-adjectives carry their own tense: drop the final い and the endings attach straight to the stem. No だ, no です needed to make a complete sentence. See the full rules in the adjective conjugation guide.

Other JLPT N1 adjectives

All JLPT N1 adjectives →