John 1:20

καὶ ὡμολόγησεν καὶ οὐκ ἠρνήσατο, καὶ ὡμολόγησεν ὅτι ἐγὼ οὐκ εἰμὶ ὁ Χριστός.

καὶ conjunction "and"

ὡμολόγησεν verb aorist active indicative 3rd singular from ὁμολογέω (I confess) "he confessed"

καὶ conjunction "and"

οὐκ negative particle "not"

ἠρνήσατο verb aorist active indicative 3rd singular from ἀρνέομαι (I deny) "he denied"

καὶ conjunction "and"

ὡμολόγησεν verb aorist active indicative 3rd singular from ὁμολογέω (I confess) "he confessed"

ὅτι conjunction "that"

ἐγὼ personal pronoun 1st person singular "I" (for emphasis)

οὐκ negative particle "not"

εἰμὶ verb present indicative 1st singular from εἰμὶ (I am) "I am"

ὁ definite article nominative masculine singular "the"

Χριστός noun nominative masculine singular "Christ"

Rough Word-by-word:
and he confessed and not he denied and he confessed that I not I am the Christ

Smooth Translation:
And he confessed and he did not deny. He confessed that, "I myself am not the Christ."