The grammar of SSE is not different from that of other versions of Standard
English around the world; in particular, constructions considered grammatical
in British English are as widely accepted as those used in American English.
Thus (1) is grammatical, as is (2).
(1) John is not going to the party, but Mary might do.
(2) John dreamed about Mary every night.
It is of course the grammar of CSE that is of more central concern here,
as it differs from its standard quite markedly. It is also relatively localised, in
that this combination of features is restricted to CSE. Many of these features,
of course, are not unusual in other varieties of English. Topic-prominence,
for instance, is found in Ghanaian English (Huber and Dako 2008), and
non-marking of the third person singular is common to many non-standard
Englishes around the world (Kortmann and Schneider 2008), but in their
combination, these and other features form the unique grammar of CSE.