Which word class is NOT included in the ten basic word classes of English?

The correct answer is Subordinators. This is because "subordinators," which are specific types of conjunctions that introduce subordinate clauses, fall under the broader category of conjunctions rather than being recognized as a separate word class. The ten basic word classes in English include nouns, verbs, adjectives, adverbs, prepositions, pronouns, conjunctions, determiners, interjections, and numerals.

While subordinators perform an essential function within sentence structure by connecting clauses, they do not comprise a distinct category, which is why they are not listed as a separate word class alongside the others mentioned.