All modal verbs are auxiliary verbs, which means they can only be used with a main verb. Modal verbs cannot be a main verb. They are used to express ideas such as possibility, prediction, speculation, deduction and necessity.
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Talk2Me English : Grammar - Repinned by Chesapeake College Adult Ed. We offer free classes on the Eastern Shore of MD to help you earn your GED - H.S. Diploma or Learn English (ESL). www.Chesapeake.edu