The copula da behaves very much like a verb or an adjective in terms of conjugation.
The main football club is da nang fc who play their home games at the chi lang stadium.
British Dictionary definitions for da
DA
abbreviation
1.
(in the US) District Attorney
2.
Diploma of Art
3.
duck's arse (hairstyle)
D/A
abbreviation
1.
deposit account
2.
(commerce) documents against acceptance
Word Origin and History for da
D.A.
American English initialism for district attorney from 1934; for duck's ass haircut (or, as OED would have it, duck's arse), from 1951. The haircut so called for the shape of it at the back of the head.