Translation of "Frail" in Japanese

He was too frail to play games outdoors.

彼はあまりにもひ弱で戸外でゲームをする事はなかった。

My grandmother was gradually becoming forgetful and frail.

祖母はだんだん忘れっぽくなり、弱ってきた。

- Because he is old, he, too, has grown weak.
- He's become frail in his old age.

彼も年のせいで弱くなった。