kare wa kodomo no koro, byoukigachi de gakkou o yoku yasunde ita.

When he was a child, he was sickly and often absent from school.

sobo wa saikin byoukigachi na node, watashitachi wa totemo shinpai shite imasu.

My grandmother has been prone to illness lately, so we are very worried.

kanojo wa byoukigachi na karada o kitaeru tame ni, maiasa jogingu o hajimeta.

She started jogging every morning to strengthen her sickly body.

izen wa byoukigachi datta ga, shokuseikatsu o kaizen shite kara sukkari kenkou ni natta.

I used to be prone to illness, but I have become completely healthy since improving my diet.

byoukigachi no imouto o sasaeru tame, ani wa isshoukenmei hataraite iru.

The older brother works hard to support his sickly younger sister.

tokai no seikatsu de sutoresu ga tamari, saikin wa byoukigachi ni natte shimatta.

Stress has built up from living in the city, and lately I have become prone to falling ill.