下定决心做某事英文怎么说

"Make a firm resolve to do something" 表示“下定决心做某事”。

来源：这是一个英语习惯用法，表示个人决定坚守信念，做到自己内心所愿。

例句：

I made a firm resolve to quit smoking.
我下定决心戒烟。
She made a firm resolve to stick to her diet.
她下定决心坚持节食。
He made a firm resolve to exercise every day.
他下定决心每天锻炼。