Σὺ (Su) in John 1:19: P-2NS

Pronoun: the word stands in for a person already addressed in the sentence, here as direct address to John.

Nominative: this form is the standard subject form, and here it helps mark the spoken question, not a different meaning of the lemma.

Singular: the form addresses one person in this exchange, matching the singular question that follows.

Common masculine form in Greek usage here: the surface form can be masculine in form, but that grammatical class does not by itself make a theological or biological claim.

The pronoun is attached to the direct question, 'Σὺ τίς εἶ;'.

It is governed by the question itself and by the implied contrastive emphasis that often appears when the subject is stated explicitly with the verb.

It identifies the one being questioned and gives force to the direct address: 'You, who are you?'

It does not by itself supply the answer, change the referent, or add a hidden title beyond the plain interrogative force of the sentence.

Moderate: The explicit pronoun sharpens the direct question about John's identity.

Explicit nominative pronoun in direct question. focuses attention on the person being questioned. Attached to the identity question addressed to John. Governed by the direct interrogative clause. Because the verb already marks second person, the explicit pronoun adds emphasis in the question.

Who is being directly questioned? The pronoun points to John as the person being asked, "Who are you?"

Direct: The form directly supports an emphatic English rendering such as "You, who are you?"

The nominative form supports subject emphasis, but it does not supply the answer to the identity question.

Case form reveals hidden identity: The pronoun focuses the address; the surrounding testimony supplies John's identity.

The witness reads 'Σὺ τίς εἶ;' after the stated purpose clause, so the form belongs to the question posed to John.

The lemma σύ is the second person singular pronoun, and this occurrence presents its nominative form as spoken address.

Because the verb already marks second person, the stated pronoun is not needed for bare grammar, so it naturally adds focus to the person being addressed.

The sentence asks John directly to identify himself, with emphasis on the person questioned rather than on any special grammatical nuance alone.

This fits the Gospel scene of inquiry and testimony, where the question is part of the witnesses' investigation of John.

In reader communication, the form can be rendered plainly as 'you' with attention to the pointed, face-to-face character of the question.

Do not derive a hidden doctrinal meaning from nominative case or from pronoun form alone, and do not read gendered theology into the grammatical form.