assure
单词辨析：
指以口头或书面形式作保证、担保、承诺，含若违背则予以补偿之意。
I can guarantee that he will pay off the debt.
我可以保证他会还清债务的。
I can't guarantee I will finish the work before dark.
我不能保证天黑前完成那项工作。
The law guarantees equal rights for men and women.
法律保证男女平等。
指用言语承诺某事一定会发生或一定是真实的，以消除他人的疑虑或担心。
I can assure you that your daughter will be happy here.
我可以向你保证，你女儿在这里会很快乐的。
We assured the tourists of an enjoyable holiday.
我们使游客确信准能过一个愉快的假期。
较正式用词，指向他人保证某人或某事物可靠、没有问题等。
certify sb's honesty and reliability
担保某人诚实可靠
I certify on my honour that she is innocent.
我用名誉担保她是清白无辜的。
指保证一定会做某事或提供某物，或某事一定会发生，侧重于自己的主观意向，用言语使人感到放心。
He promised to return the money to me.
他保证把钱还给我。
He promised her that he would marry her.
他保证要娶她。
指以发誓的形式作出保证，或强调自己所说的是真话。
He swore that he would get his revenge.
他发誓要报仇。
I never touched his wallet, I swear!
我绝没有碰过他的钱包，我发誓！
He swore never to gamble again.
他发誓再也不赌博了。
相关例句：
The doctor tried to assure me, saying it was nothing serious.
医生设法使我放心，说是情况不严重。
'Are you sure the raft is safe?' she asked anxiously. 'Couldn't be safer,' Max assured her confidently
“你确定木筏安全吗？”她不安地问道。“再安全不过了，”马克斯信心十足地向她保证道。
I assure you that she can be trusted to do the job.
我担保她能做好这项工作。
I assure you that we can arrive on time.
我保证我们可以按时到达。
This may sound trivial, but I assure you it is quite important!
这听上去也许微不足道，但是，相信我，它十分重要！
I assure you that I shall be here at midday tomorrow.
我向你保证明天中午我一定到这儿。