on; on top; upon; first (of two parts); previous or last (week etc); upper; higher; above; previous; to climb; to go into; above; to go up; to attend (class or university); third tone of putonghua[cedict]
事儿
shì ㄕˋ
one's employment; business; matter that needs to be settled; erhua variant of 事, thing, matter, affair etc[cedict]