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.
The company improved working conditions.
To improve a skill or ability through effort. Often used for language, sports, or arts.
To make improvements to a product, machine, or method, often through innovation or redesign.
The engineer improved the software.
To raise the level or quality of something, often used for skills, morale, or standards.
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).
To recover or get better from illness, injury, or a bad state.
To recover, get better (health, economy, etc.).
To make small adjustments to perfect something, like a speech, plan, or appearance.
To polish, refine, or brush up (skills, appearance, etc.).
改善する is for abstract improvements (systems, conditions), while 改良する is for concrete, often technical improvements (products, machines).
Improve business processes.
I want to improve my Japanese by practicing every day.
We improved employee skills with new training.
How can I improve this room?
The work environment is gradually improving.
To improve in a skill or ability (intransitive). The subject is the person or the skill.
His Japanese improved remarkably.
Common, versatile intransitive verb meaning 'to get better'. Used for health, weather, situations, etc.
The weather improved.
To rise in level or quality, often used for skills, standards, or morale.
The standard of living improved.
To make progress, advance. Often used for technology, science, or personal development.
Medicine is improving rapidly.
He recovered from his illness.
To heal, get well (for injuries or illnesses). Intransitive.
My cold got better.
To be on the mend, heading toward recovery. Slightly formal.
His condition is improving.
To improve one's presentation skills.
To knead, elaborate, or polish (a plan, idea, wording).
We need to improve the plan further.
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.
Improve one's Japanese.
The economy is improving.
回復する is common for economic recovery.