I’'ll just go and check on the children.我正要去看看孩子們（是否都安全）。
check out 調查，
The polic are checking out his alibi.警察在調查他的不在場證據
check over/through 仔細檢查，核對（從頭到尾仔細檢查壹遍，看能不能發現什麽）
Please check over your homework for mistake before you hand in.在交上作業之前先檢查下有沒有錯誤。
check up on sth 查證，核實;監督，督促
My parents are always checking up on me.我父母總監督我。
I need to check up for a few things before I can decide.