意思都不一样.
ensure
1. 保证;担保[O9][+that][+v-ing]
I can't ensure his being on time.
我不能保证他的准时.
I can't ensure that he will be there on time.
我不能担保他会及时到那儿.
This medicine will ensure you a good night's sleep.
这药将保证你一晚睡眠良好.
2. 使安全,保护[Q][(+from/against)]
These are safety devices to ensure workers against accidents.
这些安全设施是为了保护工人不出事故.
assure
1. 向...保证,担保[(+of)]
I can assure you of the reliability of the information.
我向你保证这消息可靠.
The captain of the ship assured the passengers that there was no danger.
船长向乘客保证没有危险.
2. 使确信,使放心[(+of)]
We assured our clients of an enjoyable holiday.
我们使游客确信准能过一个愉快的假期.
3. (后接oneself)使弄清楚,使确定
They assured themselves that the bridge was safe before crossing it.
他们直到弄清楚那座桥确实安全后才通过.
4. 确保,保障
Her future was assured.
她的未来是有保障的.
5. 保证给予
make sure
1. 查明;设法确保,确定
You must make sure of the time and place.
你必须把时间和地点弄清楚.