Translation guide
The English word "simple" covers several related ideas: not complicated, easy, plain, and sometimes naive. This guide helps you choose the right Japanese expression for each meaning.
Describing tasks, explanations, or things that are straightforward and not difficult.
The most common and versatile word for 'simple' in the sense of 'easy' or 'not complicated'. Used for tasks, problems, explanations, etc.
この問題は簡単です。
This problem is simple.
料理は簡単だった。
The cooking was simple.
Means 'easy' rather than 'simple', but often overlaps. Use when emphasizing lack of difficulty.
この本は易しいです。
This book is simple (easy to read).
Means 'simple' in the sense of 'uncomplicated' or 'plain'. Often used for structures, mechanisms, or ways of thinking. Can sometimes imply 'simplistic' or 'naive'.
仕組みは単純です。
The mechanism is simple.
Describing appearance, design, or style that is not elaborate.
A loanword from English, very common for 'simple' in design, fashion, or lifestyle. Carries a positive nuance of clean and uncluttered.
シンプルなデザインが好きです。
I like simple designs.
部屋をシンプルに保つ。
Keep the room simple.
Means 'simple' in a modest, frugal, or austere way. Often used for lifestyle, meals, or clothing. Can be positive (humble) or neutral.
Means 'plain' or 'sober' in appearance. Often used for colors, clothes, or makeup. Can have a slightly negative nuance of 'dull'.
Describing systems, processes, or structures that are uncomplicated.
Describing a person or idea that is overly simplistic or foolish.
Used for emphasis to mean 'just' or 'only', often in expressions like 'a simple mistake'.
A pre-noun adjectival meaning 'mere' or 'simple'. Used to downplay something.
それは単なる間違いだ。
It's a simple mistake.
Means 'just a little' or 'mere'. Often used with small quantities or trivial things.
ほんのちょっとしたことです。
It's a simple little thing.
簡単 (かんたん) is the safest choice for 'simple' meaning 'easy'. 単純 (たんじゅん) emphasizes lack of complexity and can be negative (simplistic). シンプル is a positive loanword for design/lifestyle simplicity.
If you mean 'naive', use 単純な人. If you mean 'humble/modest', use 質素な人. Saying 簡単な人 is unnatural.
Eat a simple meal.
She is wearing clothes in simple (plain) colors.
操作は簡単です。
The operation is simple.
That's a simple (foolish) idea.