John 1:21

No, No; Yes, Yes

Greek Οὐκ εἰμί, A phrase starting with Οὐκ generally implies a question. "Am I not?" For example, 1 Corinthians 3:16, 6:15, etc, Οὐκ οἴδατε "do you not know/see?"

Greek Ὁ προφήτης εἶ σύ (Ho prophētēs ei sy) translates literally to "The Prophet you are being yourself."

Greek Καὶ ἀπεκρίθη oὔ. And he separated 'no'. ἀπεκρίθη is a passive aorist meaning to separate, set apart. Οὔ is a particle of negation. This form is found around 700 times, the vast majority of times it negates—"not".