Translation guide
This guide covers how to express 'become weak' in Japanese, focusing on physical strength, intensity, influence, and abstract qualities. It includes common verbs, adjectives, and set phrases, organized by the type of weakness.
Describing a person, animal, or body part losing physical power or stamina.
The most general and neutral way to say 'become weak' physically. Uses the adjective 弱い (weak) + なる (become).
As you get older, your physical strength becomes weak.
My legs became weak due to illness.
Often used for a gradual decline in strength, especially due to age or illness. More formal/literary than 弱くなる.
My grandmother's legs and lower back have become weak.
Intransitive verb meaning 'to weaken' or 'to become weak'. Often implies a noticeable decline in condition.
The dog is becoming weak from the heat.
Describing a force, signal, light, sound, or effect losing strength.
Describing a person, group, or country losing power, authority, or influence.
Describing a weakening of resolve, will, memory, or other intangible attributes.
Describing currency, market, or economic strength declining.
弱くなる is the most versatile and neutral. 衰える implies a gradual decline, often due to age or illness, and is slightly formal. 弱る focuses on a noticeable state of weakness, often temporary.
Physical strength declines with age.
The dog is weakened by the heat.
English 'become weak' often maps to adjective + なる (弱くなる) or specific intransitive verbs. Using a single verb like 弱る may not fit all contexts. Pay attention to what is becoming weak.
台風の勢力が弱まった。
The typhoon's strength weakened.
記憶が薄れてきた。
My memory is becoming weak/fading.
Stock prices fell and the market became weak.