保证做某事用英文怎么说

"Guarantee" 或 "ensure" 可以用来表示 "保证做某事"。

来源：
"Guarantee" 源自拉丁语 "garantia"，意思是 "担保"。
"Ensure" 源自拉丁语 "in-" 和 "securus"，意思是 "使安全"。

例句：

I guarantee that I will finish the report by next Friday. (我保证下周五前完成报告。)
We will ensure that all customers receive their orders on time. (我们将保证所有顾客及时收到订单。)
Can you guarantee the quapty of your products? (你能保证你的产品质量吗？)
We ensure the safety of our employees by providing regular training. (我们通过提供定期培训来确保员工的安全。)