sit (someone) up
phrasal verb with sit verb uk/sɪt/ us/sɪt/ sitting | sat
(使)坐起来;(帮某人)坐起来
to move into a sitting position after you have been lying down, or to help someone else to do this
Let me sit you up in the bed so you'll be more comfortable. 我帮你从床上坐起来吧,这样你会更舒服些。