English is not my native language so I cannot comment on the quality of it but Apple includes some basic grammar checking. It looks like it is able to catch so

English is not my native language so I cannot comment on the quality of it but Apple includes some basic grammar checking. It looks like it is able to catch some basic things like "is" / "are" or "a" / "an". (This counts as grammar, right?) Someone who knows the traps of the English language who can test / comment on this feature?