1. Of or pertaining to grammar; of the nature of grammar; as, a grammatical rule.
2. According to the rules of grammar; grammatically correct; as, the sentence is not grammatical; the construction is not grammatical.
--Gram*mat*ic*al*ly, adv. -- Gram*mat*ic*al*ness, n.
adv : in a grammatical manner; "this child already speaks
grammatically" [ant: ungrammatically]