Subject + 上床
上床 (shàngchuáng) literally means 'to get onto a bed' and is used to express the action of going to bed or lying down. It combines the directional verb 上 (to go up/onto) with 床 (bed). In casual usage, it can also carry a colloquial connotation beyond simply sleeping.
我昨晚十一点就上床了,但翻来覆去睡不着。
wǒ zuówǎn shíyī diǎn jiù shàng chuáng le, dàn fānláifùqù shuì bù zháo.
I went to bed at eleven last night, but I tossed and turned and couldn't fall asleep.
孩子们,快去刷牙上床吧。
háizimen, kuài qù shuā yá shàng chuáng ba.
Kids, hurry up and brush your teeth and go to bed.
他太累了,回家倒头就上床睡觉了。
tā tài lèi le, huí jiā dào tóu jiù shàng chuáng shuìjiào le.
He was so tired that he went straight to bed as soon as he got home.