The word "boy" is a noun. A boy is a person.
Adjective
Boys is a noun. It's the plural form of boy.
It's a pronoun.
"Little" is an adjective, describing the boy. "Boy" is a noun, referring to a young male.
the subject
PREPOSITION
third person singular verb
Conjunction
Comes is a verb in that sentence.
Trace is a verb and a noun.Verb: The boy traced the picture.Noun: The ship disappeared without a trace.
"Unusual" is used as an adjective. e.g. The unusual boy stuttered as he spoke. "unusual" is modifying "boy". Only adjectives modify nouns and pronouns.
part of speech