悪(わる)い

悪(わる)い is the general adjective of negative evaluation, the opposite of いい/よい (good). It covers poor quality, poor condition, and moral wrongness, and in casual speech it doubles as an admission of fault ('sorry').

Usage

• As a predicate, what is bad is marked with が: 天気(てんき)が悪(わる)い (the weather is bad).
• Before a noun, 悪(わる)い usually carries the moral sense: 悪(わる)い人(ひと) (a bad person), 悪(わる)いこと (a bad deed, wrongdoing).
• 悪(わる)くない is literally 'not bad,' but in conversation it is mild praise, closer to 'pretty good' than to 'not good.'
• 気(き)を悪(わる)くする means 'take offense,' not 'make something worse.'

Common collocations

• 天気(てんき)が悪(わる)い: bad weather
• 目(め)が悪(わる)い: poor eyesight
• 調子(ちょうし)が悪(わる)い: not feeling well / not working properly
• 具合(ぐあい)が悪(わる)い: in poor condition (health or machinery)
• 都合(つごう)が悪(わる)い: inconvenient, a bad time
• 頭(あたま)が悪(わる)い: not smart (can be offensive)
• 仲(なか)が悪(わる)い: on bad terms (relationship)

AS APOLOGY (casual):
In this use 悪(わる)い means 'I am in the wrong,' not 'bad in quality,' so it admits fault rather than describing something.

• 悪(わる)い!: Sorry! My bad!
• 悪(わる)いね: Sorry about that
• 悪(わる)いけど...: Sorry, but...

These are casual and are used mainly by men and among close friends. For polite apologies, use すみません or ごめんなさい.