快適(かいてき)

Forms

快(かい) (pleasant) + 適(てき) (suitable).

Usage

快適(かいてき) describes conditions, environments, and equipment - a room, a climate, a seat, a commute - not people. There is no ×快適(かいてき)な人(ひと), and a speaker does not normally use it of their own momentary feeling either; for that, use 気持(きも)ちいい. It is a slightly formal, written-leaning word, at home in product copy, travel writing, and reviews.

Grammatical forms

• Modifier: 快適(かいてき)な部屋(へや) (a comfortable room)
• Predicate: 部屋(へや)が快適(かいてき)だ (the room is comfortable)
• Adverb: 快適(かいてき)に過(す)ごす (spend time comfortably)
• Noun: 快適(かいてき)さ (comfort, the quality of being comfortable)

Common collocations

• 快適(かいてき)な環境(かんきょう) (comfortable environment)
• 快適(かいてき)な空間(くうかん) (comfortable space)
• 快適(かいてき)な生活(せいかつ) (comfortable life)
• 快適(かいてき)な睡眠(すいみん) (good sleep)
• 快適(かいてき)な乗(の)り心地(ごこち) (a comfortable ride)
• 快適(かいてき)さを求(もと)める (to seek comfort)

Similar words

• 心地(ここち)よい - pleasant to the senses; a breeze or a sound can be 心地(ここち)よい but not 快適(かいてき)
• 居心地(いごこち)がいい - specifically about how it feels to stay somewhere, including the social atmosphere
• 楽(らく) - comfortable in the sense of requiring little effort or strain
• 便利(べんり) - convenient; about usefulness rather than physical comfort

不快(ふかい) (unpleasant, disagreeable).