我保证

• by my troth

例句

1. 不客气。我保证您会发现我们产品的前景非常美好。
   My pleasure. I can assure you that you'll find very good prospects in our products.
2. 我保证我没有告诉过任何人。
   I didn't tell anyone, on my oath.
3. 他向我保证星期五一定准备好。
   He gave me an assurance that it would be ready by Friday.