| Syntactically, the modal auxiliary verbs discussed here appear below both epistemic adverbs and negation. |
| These are less confined in their selectional restrictions than modal auxiliary verbs. |
| English also has a rich set of auxiliary verbs, such as have and do, expressing the categories of mood and aspect. |
| When writing the rule, always use the base form of the main verb and any auxiliary verbs. |
| They begin to flesh out their noun-verb sentences with less critical words such as prepositions, conjunctions, articles, and auxiliary verbs. |
| In clauses with auxiliary verbs they are the finite verbs and the main verb is treated as a subordinate clause. |
