Ada, used together with either a VP predicate or AP predicate, serves as an emphatic marker, denoting the assertion or affirmation of the state or event mentioned in the sentence. In this sense, the role of ada in Bazaar Malay is somewhat similar to that of emphatic do in English, as in the following:
(1) He did say he would be here at nine, didn’t he?
(Quirk et al. 1986: 79)
2. Do sit down.
(Quirk et al. 1986: 79)
The crucial difference is that in Bazaar Malay, ada as the emphatic marker always
affirms a situation in the past when the predicate is a VP. When the AP-predicate is
used, the time frame is decided upon by context.
Source: Aye 2005: 174