John's characteristic combination of a positive and negative clause. See on Joh 1:3. Both verbs are used absolutely.
I am not the Christ
According to the proper reading, ἐγὼ, I, stands first in the Baptist's statement, the ὁÌτι having the force merely of quotation marks. It is emphatic: “I am not the Christ, though the Christ is here.†Some were questioning whether John was the Christ (Luk 3:15; Act 13:25). Note the frequent occurrence of the emphatic I: Joh 1:23, Joh 1:26, Joh 1:27, Joh 1:30, Joh 1:31, Joh 1:33, Joh 1:34. On the Christ, see on Mat 1:1.