'Shàng cì' literally combines 'shàng' (meaning 'previous' or 'above') and 'cì' (meaning 'time' or 'occasion'), forming a compound noun that means 'last time' — referring to the most recent prior occurrence of an event. It functions as a temporal noun phrase and typically appears before verbs or at the beginning/middle of a sentence to anchor the action in the immediate past.

Unlike 'zuó tiān' (yesterday) or 'shàng zhōu' (last week), 'shàng cì' is relative and context-dependent: it points to whichever event was most recently discussed or experienced, regardless of elapsed time. It’s neutral in register — common in both spoken and written Chinese — and often used when recalling shared experiences, reviewing past actions, or contrasting previous and current situations. It cannot stand alone as a subject without context but pairs naturally with verbs like 'jiàn', 'qù', or 'shuō'.