gram·mat·i·cal 
(grə-mătĭ-kəl)
(grə-mătĭ-kəl)adj.
1. Of or relating to grammar.
2. Conforming to the rules of grammar: a grammatical sentence.
[Late Latin grammaticālis, from Latin grammaticus, from Greek grammatikos, of letters; see GRAMMAR.]
gram·mat′i·cali·ty (-kălĭ-tē) n.
gram·mati·cal·ly adv.