这三个动词是同型词，词义也相近，都可表示 “保证” 的意思，容易误用。

assure 主语是人时，表示向某人保证某事，以消除疑虑，使人确信或放心 (to tell

someone everything's OK)

常用结构是：

assure sb. that ……

The captain of the ship assured the passengers that there was no danger.

船长向乘客保证没有危险。

Before going to bed she assured herself that the door and windows were properly

closed.

睡觉之前她确定门窗已经完全关闭好了才放心。

The doctor assured him that his child would recover from the illness soon.

医生担保说他的孩子会很快康复的。

I can't force you to make a deal, but I can assure you that our product has the edge

on the competition.

我不能强迫您买，但是我可以向您保证我们产品是很具有竞争力的。

______________

assure sb. of sth.

I can assure you of the accuracy of the figures used in the report. I have checked

them time and again.

我可以向你保证用于报告的数据是准确的，我已再三检查过了。

We booked early to assure ourselves of good seats．

我们及早订座以保证我们能得到好座位。

I can assure you of our best intentions and closest cooperation. We're always

willing to develop trade with friends from all over the world.

请相信我们一定会竭尽全力密切合作的，我们一向愿意和世界各国朋友开展贸易。

Picasso’s artistic genius and achievement assured him of a dominant place in the

history of modern art.

毕加索的艺术天才和成就确定了他定在中国现代艺术历史中的地位。

_______________

assure 主语是物时，确保”、“保障”、“使确定”是意思，常接名词作宾语。

例句：

A last-minute deal assured the company's future.

最后一刻达成的协议保证了公司的未来。

An anonymous donation assured the museum's long-term future.

一笔匿名捐赠保证了博物馆的长远发展。

It is always difficult to assure good insulation between the electric leads.

要保证两个电触头之间有良好的绝缘总是很困难的。

Something should be done to assure the peace in the region.

须采取措施确保该地区的和平。

Weeks of intense practice assured success in the match．

几个星期的强化训练确保了在比赛中获得成功。

ensure “保证”，指保证某行为或某事有结果(to make sure that something will

happen) 。 ensure 的主语或逻辑主语通常的人或组织。

1）接直接宾语，即 ensure sth.

The airline is taking steps to ensure safety on its aircraft.

航空公司正在采取措施以确保其航班的飞行安全。

To ensure the child’s quick recovery，the doctor gave him an antibiotic．

为使这个孩子尽快恢复，医生给他打了一剂抗生素。

What we all desire is to prevent the recurrence of these incidents and to ensure the

security of the area.

我们都渴望能防止这类事件的再次发生以确保该地区的安全。

But compulsory measures may also be necessary to ensure consistent, universal

implementation of these steps.

但是，也有必要采取强制手段来确保这些举措持续和全面的执行。

——————

2）接 that 从句， 即 ensure that ……

The role of the police is to ensure that the law is obeyed.

警察职责的就是确保法律得到遵守。

She said that he would go to any length to ensure that his child gets a good

education.

她说他会竭尽全力确保他的孩子获得良好的教育。

To ensure that you do a good job in the examination tomorrow, you’d better have

go to bed early tonight.

为了确保明天你考好试，今晚你最好早点睡觉。

Efforts should be made to ensure that state-owned enterprises compete on the same

terms with private companies on the same terms.

要努力确保国有企业与私营公司在相同的条件下进行竞争取。

——————

3） 接双宾语，即 ensure sb. sth.

This medicine will ensure you a good night’s sleep.

这药会保证你今晚好好睡一觉。

We can ensure you regular supplies of these materials if you pay for them in good

time.

如果你们能按时付款，我们可以保证定期向你们供应这些材料。

These documents can ensure you the authority you need in your business.

这些文件可以确保你业务中所需要的权威性。

———————

4）ensure …… against 是常用搭配，表示保证某人或某物不受到伤害或危险。

The engineers have used special methods to ensure the bridge against danger

from high winds.

工程师们已经使用特殊方法确保桥梁不受大风对其危险的影响。

Code reviews are the most effective and efficient method to validate code quality

and ensure against code defects and faults of commission.

码检查是验证代码质量并确保代码无缺陷和错误的最有效、最经济的方法。

These are safety devices to ensure workers against accidents at the worksite.

这些安全设施是为了保护工人在工作场所不出事故。

——————

● 物作主语时用法同 assure, 接直接宾语，表示“确保 guarantee”

The possession of large amounts of money does not ensure/assure happiness.

坐拥巨额财富并不能保证幸福。

The only ladder to assure/ensure success is to work hard.

确保成功的唯一途径是努力工作。

insure

1）主要用作“保险”，指为防不测向保险公司付钱投保。表示“对……保险”常用

insure against。

例句：

My house is insured against fire．

我的房子保了火险。

The company has insured its property for 2 million dollars.

公司投了200万美元的财产保险。

We’d better insure the goods, in case something happen during the transportation.

我们最好投保这批货，以防在运输途中出事。

Every father should insure himself against premature death or prolonged illness for

the sake of his wife and children.

每个父亲都应该对自己可能早丧和长期卧病为妻子和孩子投保。

If you desire us to insure against a special risk, an extra premium will have to be

charged.

如你想投保特殊险别，将向你收取额外保费。

———————

2）为（某人或某物）提供保险；承保 （to provide insurance for someone or

Something）

例句：

Many companies won't insure new or young drivers.

许多公司不给新司机或年轻司机投保。

They refused to insure us because they said we're too old.

他们拒绝给我们投保，因为他们说我们太老了。

________________

3） 美语中也可用 insure 表示“保证”，相当于 ensure 用法。

例句：

More care would insure/ensure you against so many mistakes.

多加注意就能保证你不犯这么多的错误。

Please book the necessary shipping space in advance to insure/ensure timely

dispatch of the goods ordered.

请预订所需的舱位以保证及时装运所订购的货物

We insure/ensure that the unqualified product in quality can be exchanged.

我们保证更换质量不合格的产品。