The citizens were tired and submissive.
The dog was submissive to its owner when it rolled over and exposed its belly.The citizens were tired and submissive.
The citizens were tired and submissive.The other dogs in the pack were submissive to the dominant alpha male.
"Ponyboy gave a submissive look." is the sentence
When it has a subject, verb, punctuation, capitalization, a predicate, and a complete thought. A sentence is a sentence when it is handed down by a judge (or a magistrate).