Translation guide
In Japanese, adjectives are a distinct word class that conjugate for tense and polarity. There are two main types: i-adjectives (which end in い) and na-adjectives (which require な when modifying nouns). This guide covers how to use adjectives naturally in Japanese, including common patterns, conjugation, and pitfalls for English speakers.
The learner wants to modify a noun with an adjective, e.g., 'a big dog', 'an interesting book'.
For i-adjectives, simply place the adjective in its dictionary form directly before the noun. No additional particle is needed.
For na-adjectives, attach な between the adjective and the noun. The な is a form of the copula and is required in this position.
Some English adjectives correspond to Japanese nouns followed by の. This is common for colors, materials, and some abstract qualities.
The learner wants to say something is [adjective], e.g., 'The dog is big', 'This book is interesting'.
The learner wants to say something is not [adjective], e.g., 'not big', 'not quiet'.
Replace the final い with く and add ない for plain negative. Polite forms: くありません (formal) or くないです (common).
The learner wants to say something was [adjective], e.g., 'was big', 'was quiet'.
The learner wants to turn an adjective into an adverb to modify verbs, e.g., 'quickly', 'quietly'.
The learner wants to compare using adjectives, e.g., 'bigger than', 'the most interesting'.
Use より to mark the standard of comparison. The adjective remains in its base form.
犬は猫より大きいです。
Dogs are bigger than cats.
この部屋はあの部屋より静かです。
This room is quieter than that room.
The learner wants to list multiple adjectives or connect an adjective clause to another clause, e.g., 'big and heavy', 'quiet and calm'.
The learner wants to avoid common mistakes when translating English adjectives directly.
English 'good' and 'bad' often map to specific Japanese adjectives depending on the noun. For example, 'good weather' is 天気がいい, not 良い天気 (though possible, it's less natural). 'Bad weather' is 天気が悪い.
A common mistake is to say 大きいだ or 楽しいだ. I-adjectives already contain the copula element and do not need だ. The polite form is 大きいです, not 大きいだです.
I-adjectives always end in い in their dictionary form (e.g., 高い, 楽しい). Na-adjectives may end in い but are not true i-adjectives (e.g., きれい, 嫌い). Na-adjectives require な when modifying nouns and だ/です in predicates. When learning a new adjective, confirm its type.
きれいな花
a beautiful flower (きれい is na-adjective)
Na-adjectives require a copula (です or だ) to end a sentence. The adjective stem is used without な.
この場所は静かです。
This place is quiet. (polite)
この場所は静かだ。
This place is quiet. (plain)
Attach ではない (plain), ではありません (polite), or the contracted じゃない (casual) to the na-adjective stem.
Attach だった (plain) or でした (polite) to the na-adjective stem.
Attach に to the na-adjective stem to form the adverbial form.
This pattern emphasizes A as the one with more of the quality.
犬のほうが猫より大きい。
Dogs are bigger than cats (emphasizing dogs).
Use 一番 (いちばん) before the adjective to mean 'the most'. For na-adjectives, な is needed when modifying a noun.
The te-form of na-adjectives is formed by adding で to the stem. It functions similarly to i-adjective te-form.
静かで落ち着いた場所
a quiet and calm place
便利でよく使う。
It's convenient, so I use it often.
In Japanese, 'like' and 'dislike' are expressed with na-adjectives 好き (すき) and 嫌い (きらい), not verbs. They follow na-adjective patterns.
猫が好きです。
I like cats.
納豆は嫌いじゃない。
I don't dislike natto.
a beautiful flower (美しい is i-adjective)
a beautiful flower (美しい is i-adjective)