'Following' describes the noun 'items'. It is a participle functioning as an adjective.

'Whoever' refers to any person who fits the description, making it indefinite.

Here, 'very' modifies the adverb 'fast', indicating degree. It is an adverb.

Unusually, 'very' can be an adjective when used to emphasize a noun (meaning 'exact' or 'actual').

Here, 'Home' is the subject of the sentence. It functions as a noun.

Here, 'home' indicates the direction/place of the verb 'went' without a preposition. It functions as an adverb.

'A' is an indefinite article, which is a type of determiner.

You can count 'songs' (one song, two songs). Music, advice, and furniture are non-count nouns.

'Worth' is unique; it functions like an adjective (describing the book) but takes a complement ('reading') like a preposition. It is often called an adjective.

'Talking' functions as the direct object of the verb 'kept'. It is a gerund.