A class of Japanese adjectives that inflect and typically end in "~i" (e.g. takai, hayai). Often called "i-adjectives" in grammar instruction.
「高い」はイ形容詞で、過去形は「高かった」になる。
"Takai" is an i-adjective; its past form is "takakatta."
イ形容詞は語尾の「い」を変えて肯定・否定・時制を表す。
I-adjectives change the ending "-i" to express affirmation, negation, and tense.
JSLの教科書では、学習者向けにイ形容詞という呼び方がよく使われる。
In JSL textbooks, the term "i-adjective" is often used for learners.