Question

Identify the part of speech of the italicized word. She pens her letters very neatly.

Answer 1

She (pronoun) pens (verb) her (pronoun) letters (noun) very (adverb) neatly (adverb).
   A pronoun is there in place of a noun. A verb is an action word, meaning it describes the action of the noun. An adverb is in a sentence to help describe the verb. A noun is a person, place, or a thing.

Answer 2

Pens is the italicized word..

Even though "pen" is usually a noun, in this case it indicates action: writing. So it is a verb.