Possible Clues:

• 'Who's there?' answer
• Informally formal entry announcement
• Stilted-sounding reply to "Who's there?"
• 'Who's there?' reply
• 'Me here!'
• Odd-sounding albeit grammatical answer to 'Who's there?'
• Grammatically correct (but really awkward) way to introduce yourself
• Grammatically correct reply to "Who's there?"
• Formal/informal response to 'Who's there?'
• 'Me here!,' more grammatically