Subject + 住院
住院 (zhùyuàn) means "to be hospitalized" or "to be admitted to the hospital." It is a verb-object compound where 住 means "to stay" and 院 refers to a hospital. It is used to describe someone being checked into a hospital for treatment or observation.
他爷爷上周住院了,我们轮流去照顾。
Tā yéye shàng zhōu zhùyuàn le, wǒmen lúnliú qù zhàogù.
His grandfather was hospitalized last week, and we take turns looking after him.
医生说她需要住院观察两三天。
Yīshēng shuō tā xūyào zhùyuàn guānchá liǎng sān tiān.
The doctor said she needs to be hospitalized for observation for two or three days.
住院期间不能用手机,他快无聊死了。
Zhùyuàn qījiān bù néng yòng shǒujī, tā kuài wúliáo sǐ le.
He couldn't use his phone during his hospital stay and was bored to death.