adverb
Prior to some specified time, either past, present, or future; by this time; previously.
So soon.
(US, Canada) An intensifier used to emphasize impatience or express exasperation.
(Singapore, Singlish) Indicates the completion of an action (whether past or hypothetical), or more generally, perfective aspect.
(Singapore, Singlish) Marks a change in state, more or less in the same manner as the inchoative aspect.