Final answer:
The verbal in the sentence 'the children went to sleep dreaming of the party' is a present participle modifying the noun 'children'.
Step-by-step explanation:
The phrase 'the children went to sleep dreaming of the party' includes a participle, a type of verbal that is behaving like an adjective. In this case, 'dreaming' is a present participle because it is formed from a verb (to dream) and is acting as an adjective, modifying the noun 'children' by telling us what they are doing as they went to sleep. Verbals are interesting elements of English grammar as they are forms derived from verbs but are not used as verbs in the sentence; instead, they function as nouns, adjectives, or adverbs.