An, from a nominative in a

Ending a word is short, they say,

But every an for long must pass

Derived from nominative in as.

Nouns, too, in en are short whose finis

Doth in the genitive make inis.

And so are n’s that do delight ĭn

An i and y—Alexĭn, Ity̆n.

Greek words are short I’d have you know,

That end in on with little o,