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.
This problem is simple.
Means 'easy' rather than 'simple', but often overlaps. Use when emphasizing lack of difficulty.
Means 'simple' in the sense of 'uncomplicated' or 'plain'. Often used for structures, mechanisms, or ways of thinking. Can sometimes imply 'simplistic' or 'naive'.
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.
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'.
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.
The cooking was simple.
この本は易しいです。
This book is simple (easy to read).
仕組みは単純です。
The mechanism is simple.
I like simple designs.
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.
Eat a simple meal.
Means 'plain' or 'sober' in appearance. Often used for colors, clothes, or makeup. Can have a slightly negative nuance of 'dull'.
She is wearing clothes in simple (plain) colors.
Focuses on the lack of complexity in structure or logic. Good for machines, rules, or reasoning.
The rules are simple.
Also works here, but emphasizes ease of use or understanding rather than structural simplicity.
The operation is simple.
Can mean 'simple-minded' or 'naive'. Often used in phrases like 単純な人 (a simple person) or 単純に考える (think simplistically).
He is a simple man.
Means 'foolish' or 'stupid'. Stronger and more negative than 単純. Use with caution.
That's a simple (foolish) idea.
A pre-noun adjectival meaning 'mere' or 'simple'. Used to downplay something.
It's a simple mistake.
Means 'just a little' or 'mere'. Often used with small quantities or trivial things.
It's a simple little thing.