If you assure someone that something is true or will happen, you tell them that it is definitely true or will definitely happen, often in order to make them less worried. (向…) 保证
verb [vt. 及物动词]使确信,向……保证;确保,使确定;给……保险
He hastened to assure me that there was nothing traumatic to report. 他急忙向我保证没有任何不快的事要报告。