Translation guide
Describes a person who is physically frail, gets sick easily, or has low stamina. Japanese expressions range from clinical terms to casual descriptions of being 'delicate' or 'weak-bodied'.
Describing someone whose body is inherently weak, prone to illness, or lacking physical strength.
The most common and natural way to say someone has a weak constitution. Literally 'body is weak'. Used for both chronic frailty and temporary susceptibility.
He has a weak constitution and often catches colds.
I had a weak constitution as a child.
A more formal or medical term for a constitutionally weak body. Often used in health contexts or when discussing chronic conditions.
She has a weak constitution and can't overexert herself.
Describes someone who is sickly or prone to illness. Often used for children or as a general adjective.
I was a sickly child, but I'm healthy now.
Similar to 体が弱い but emphasizes the constitutional aspect (体質 = constitution). Slightly more formal.
Since I have a weak constitution, I'm careful about my diet.
Emphasizing delicateness, often with a nuance of needing protection or being easily affected by environment.
Means physically weak, frail, or delicate. Often implies a lack of strength or stamina, sometimes with a negative connotation of being feeble.
I want to strengthen my frail body.
He is more delicate than he looks.
Describes something as weak and delicate, often evoking a sense of pity or protectiveness. Commonly used for women, children, or small creatures.
Means weak, soft, or lacking firmness. Can refer to physical weakness or a weak character. Slightly negative.
Focusing on lack of endurance or getting tired quickly, rather than illness.
Literally 'have no physical strength/stamina'. The most direct way to say someone lacks endurance or gets tired easily.
I have no stamina and get tired quickly.
Uses the loanword 'stamina'. Casual and common in spoken Japanese.
I have no stamina and can't run for long.
体が弱い is the everyday expression for having a weak body or getting sick often. 虚弱体質 is a more clinical term for a constitutional weakness, often used in medical or formal contexts.
Do not translate 'weak constitution' directly as 弱い憲法 (which means 'weak constitution' as in a country's constitution). Always use expressions related to body or health.
か弱い体で必死に戦った。
She fought desperately with her frail body.
軟弱な体質を改善する。
Improve a weak constitution.