ensures

"The condition for getting a raise at work is meeting your quarterly targets. "

"My friend told me there was something in the box, but I didn't know what it was yet. "

"My teacher explained the new math concept, and I understood it perfectly. "

"Do you need a gift for that special someone?"

"Can you give me a guarantee that he will be fit for the match?"

"Except for one or two days a year, he usually walks to work."

"if I make a promise, I always stick to it;  he broke his promise"

"Please direct your attention to the following words."

"The student made a pledge to study harder for the upcoming exam. "

"The certain success of the project was a relief to the team. "

"The teacher assured the students that the exam would be graded fairly. "

"he paid her off the books and in kind where possible"