ought to 2022.12.06 ought toとは 意味・定義・例文 Helping verb 助動詞 1. used to show an obligation or a duty ~すべきである You ought to do your best. 2. used to show what is expected or likely ~するはずである She ought to be home by now. 3. used to offer advice ~したほうがよい It's late. You ought to go home.