select the option which is not included in the structural word category

Structure words are words belonging to the categories of articles, auxiliaries, conjunctions, prepositions and pronouns. They have a high frequency of occurrence in all styles and varieties of English.

Key Points

• Structure words provide the grammatical structure of a sentence and contribute structural meaning.
• Structure words function as structural markers which help us to recognize the part of speech to which a word or sentence belongs. 
• Words belonging to the given parts of speech fall into the structural word category-
  • Articles- the, a
  • Prepositions- and, in, through, around, with, of, to, from, except, like, for.
  • Conjunctions- but, because, and, until, how, that, so, or. 
  • Auxiliaries- could, had to, used to, would, were, am, be, can, are, may.
  • Pronouns- I, that, my, this, he, me, anything, anybody, it, him, we.
  • Interjection- hurray! ouch! wow! oh!
  • Determiner- articles, cardinal, ordinal numbers, etc.

Hence, we conclude that adverb is not included in the structural word category.

Hint

• Adverb falls into the category of lexical or content words.