Translation guide
The English verb 'strengthen' covers making something physically stronger, reinforcing structures, intensifying feelings or resolve, and bolstering arguments or relationships. Japanese uses different verbs depending on what is being strengthened and whether the change is physical, abstract, or metaphorical.
To increase physical strength, fitness, or robustness of a person, animal, or body part.
To train, discipline, or forge the body or mind through effort. Commonly used for muscles, skills, or mental fortitude.
I strengthen my body at the gym every day.
I strengthen my arms with push-ups.
A general phrase meaning 'to make strong'. Can be used for muscles, but 鍛える is more natural for intentional training.
This exercise strengthens your legs.
To strengthen, reinforce, or enhance. Often used in formal or technical contexts, including physical training programs.
training to strengthen the core
To make a building, bridge, material, or physical object stronger or more resistant to force.
To reinforce, shore up, or add strength to a structure. Used for buildings, walls, bridges, etc.
We strengthened the house in preparation for earthquakes.
construction work to strengthen the bridge supports
Also used for structural strengthening, often in technical or official contexts.
Strengthen the earthquake resistance of the building.
To make something sturdy or durable. More casual and less technical than 補強する.
I want to strengthen this shelf.
To make an emotion, determination, belief, or relationship stronger.
Transitive verb meaning to intensify or strengthen something abstract like feelings, impressions, or influence.
His words strengthened my resolve.
To deepen (a relationship, understanding, bond). Often used for mutual connections.
To solidify or firm up (resolve, determination, plans). Implies making something firm and unshakable.
Used for abstract strengthening in formal contexts, like policies, systems, or security.
We need to strengthen security.
To make a case, theory, or claim more convincing or robust.
To reinforce or back up an argument with additional evidence or reasoning.
We strengthened the hypothesis with new data.
To make something firm or solid, often used for positions or stances.
The testimony strengthened his position.
To support or corroborate with evidence. Often used in academic or investigative contexts.
To make a group, system, or skill more effective or powerful.
The standard term for strengthening organizations, teams, systems, or capabilities.
Strengthen the team's cooperation.
The company is strengthening its overseas operations.
To augment or build up, especially military forces, personnel, or resources.
Strengthen the military forces.
強める (tsuyomeru) is for abstract intensity (feelings, influence). 強化する (kyōka suru) is a formal, all-purpose 'strengthen' for systems, security, capabilities. 補強する (hokyō suru) is for physical reinforcement or backing up arguments with evidence.
While 強くする (tsuyoku suru) can mean 'make strong', it sounds unnatural for emotions or arguments. Use 強める or 強化する instead.
The incident strengthened people's anxiety.
交流を通じて友情を深めた。
We strengthened our friendship through interaction.
決意を固めて留学した。
I strengthened my resolve and studied abroad.
This fact strengthens his claim.