Translation guide
The English verb 'improve' covers making something better, getting better at a skill, or a situation becoming better. Japanese uses different verbs depending on whether the change is intentional (transitive) or natural (intransitive), and what is being improved.
To actively cause something to become better, such as a skill, condition, or quality.
General term for improving a situation, system, or condition. Often used in business or formal contexts.
会社は労働条件を改善した。
The company improved working conditions.
To improve a skill or ability through effort. Often used for language, sports, or arts.
毎日練習して、日本語を上達させたい。
I want to improve my Japanese by practicing every day.
To make improvements to a product, machine, or method, often through innovation or redesign.
エンジニアはソフトウェアを改良した。
The engineer improved the software.
To raise the level or quality of something, often used for skills, morale, or standards.
新しいトレーニングで社員のスキルを向上させた。
We improved employee skills with new training.
Casual, everyday way to say 'make better'. Can be used for various things.
To describe a situation, skill, or condition getting better on its own or without specifying an agent.
Passive form of 改善する, used when a situation improves (often due to external efforts).
労働環境が徐々に改善されている。
The work environment is gradually improving.
To improve in a skill or ability (intransitive). The subject is the person or the skill.
彼の日本語はめきめき上達した。
His Japanese improved remarkably.
Common, versatile intransitive verb meaning 'to get better'. Used for health, weather, situations, etc.
天気が良くなった。
The weather improved.
To rise in level or quality, often used for skills, standards, or morale.
生活水準が向上した。
The standard of living improved.
To make progress, advance. Often used for technology, science, or personal development.
医学は急速に進歩している。
Medicine is improving rapidly.
To recover or get better from illness, injury, or a bad state.
To recover, get better (health, economy, etc.).
彼は病気から回復した。
He recovered from his illness.
To heal, get well (for injuries or illnesses). Intransitive.
風邪が治った。
My cold got better.
To be on the mend, heading toward recovery. Slightly formal.
容態は快方に向かっている。
His condition is improving.
To make small adjustments to perfect something, like a speech, plan, or appearance.
To polish, refine, or brush up (skills, appearance, etc.).
プレゼンテーションの技術を磨く。
To improve one's presentation skills.
To knead, elaborate, or polish (a plan, idea, wording).
計画をもっと練る必要がある。
We need to improve the plan further.
改善する is for abstract improvements (systems, conditions), while 改良する is for concrete, often technical improvements (products, machines).
業務プロセスを改善する。
Improve business processes.
エンジンを改良する。
Improve the engine.
While 良くする can mean 'make better', it sounds unnatural for improving a skill. Use 上達させる or 向上させる instead.
日本語を上達させる。
Improve one's Japanese.
How can I improve this room?