The English teacher called Peter

The English teacher called Peter for a graded recitation.

“Peter, recite a sentence that begins with I.”

Peter thought for a moment and slowly said, “I is the…”

The teacher interrupted him and said,

“No, Peter. You say ‘I am’ instead of ‘I is’. Now, try again.”

“Okay,” Peter said. “I am the ninth letter of the English alphabet.”