This is the second person singular pronoun 'you,' showing the rich dialectal variation of ancient Greek. The forms varied significantly across dialects: Attic used σύ (nominative), σοῦ (genitive), while Epic and Ionic preserved forms like τύνη, σεο, and τεῦ. The accusative σε is among the most common forms in New Testament Greek. Ancient Greek carefully distinguished singular from plural second person pronouns (unlike modern English), making the singular forms crucial for indicating direct personal address to an individual rather than a group. These pronouns carried significant weight in prayer, commandments, and personal confrontation.