(1) ①swear是“发誓，保证”，指郑重地许诺做某事，是较正式的用词。
- He swore (to his father) he would never get mixed up/throw in his lot with that gang.
他(向父亲) 发誓再也不跟那帮人混在一起/一道干了。 - It was here under the big old oak tree that we had sworn never to be separated.
正是在这棵高大的老橡树下，我们山盟海誓永不分离。 - He swore eternal love to her.
他发誓永远爱她。
②swear有时用作被动式。
- They were sworn to drive the invaders out of their country.
他们发誓把侵略者从他们的国土上驱逐出去。
③swear有时表示“敢肯定，敢打赌”。
- I could have sworn that he didn't come to the meeting yesterday.
我敢打赌他昨天没来开会。 - I could have sworn /I am sure she was here a minute ago.
我可以肯定她一分钟前还在这儿。
④swear by表示“以……名义起誓，以……的名誉/人格担保”。
- He swore by God to tell/that he would tell the truth.
他以上帝的名义起誓，保证说实话。 - He swore by all the saints/by his honor that he would pay back the money within three months.
他以圣人/自己的名誉做担保将在三个月内把钱还上。
⑤swear by还作“相信，信赖，主张”解。
- My wife swears by hand-washing, and won't have a machine.
我妻子极力主张手洗衣服，而不愿买洗衣机。 - She swears by that brand.
她非常信赖那个品牌。
⑥swear in 表示“使宣誓就职”。
- At the inauguration, the Chief Justice of the Supreme Court swore in the new President.
在就职典礼上，最高法院的首席法官让新总统宣誓就职。 - The newly-elected President is being sworn in next week.
这位新当选的总统将在下周宣誓就职。
(2) ①promise意为“答应，许诺”。
- He promised (me) to see me home that day.
那天他答应(我)送我回家。 - He promised (us) that he would come to repair the roof within two or three days.
他答应将在两三天内前来修房顶。 - His father promised him a new car for his birthday.
他父亲许诺为他的生日买一辆新车。
②I promise you意思是“可以肯定；我要预先告诉你”。
- The work won't be easy, I promise you .
我要预先告诉你，这份活不好干。
③promise the moon意思是“答应办不可能办到的事”。
- I can't promise you the moon , but I'll do the best job I can.
我无法答应你去办我所不可能办到的事情，但是我会尽力而为的。
(3) ①pledge指较郑重的“誓言，保证(做或不做某事)”。
- He pledged never to come back until he had founded his own business.
他发誓干不出一番事业绝不回来。 - He pledged himself not to mention it to anybody without my permission.
他发誓未经我的允许他绝不向任何人提及此事。 - He pledged that he would return after three years' study.
他保证在学习三年后会回来的。
②pledge也可用过去分词作表语。
- We were all pledged to secrecy/to keep it a strict secret.
我们都发誓严守秘密。
③pledge与one's word (of honor), one's determination等连用，表示“提出保证，表示决心”等。
- He pledged his word (of honor) that he would be off drugs for ever.
他(以他的人格担保)发誓将永远远离毒品。 - They pledged their determination to carry through to the end the struggle for freedom, democracy and justice.
他们下定决心一定要将为争取自由、民主和正义的斗争进行到底。
(4) ①undertake除表示“从事、着手、负责、承担(责任)做某事”(接名词、代词、动名词)外，还可表示“同意、答应做某事”，接不定式。
- He undertook to pay off all his debts by the end of next month.
他同意在下月底之前还清他所有的债务。 - He has undertaken to attend the dinner party in honor of the foreign experts who are leaving here for home.
他答应参加这次为欢送回国的外国专家举行的晚宴。
②undertake还可作“保证”解，后接that从句。
- Can you undertake that the entire task will be accomplished in time?
你能保证所有的任务都能按时完成吗？ - I can undertake that your health will be greatly improved by doing calisthenics.
我能保证做柔软体操会大大改善你的健康状况。
(5) guarantee可作“(做出)保证，担保，保修”解，可接名词、代词、双宾语、that从句和不定式。
- The manufacturer guarantees the air-conditioner for 18 months.
制造商为此空调保修18个月。 - All sides at the conference agreed unanimously to guarantee the territorial integrity of this country.
与会各方一致同意保证这个国家的领土完整。 - Nobody can guarantee the punctual arrival of the train in such weather.
这种天气没人能保证火车的准点到达。 - I'll lend you the car provided you guarantee that you'll return it tomorrow.
只要你能保证你明天将车还给我，我就把车借给你。 - I guarantee to fulfill the task within 2 or 3 days.
我保证在两三天内完成这项工作。
(6) warrant用作动词时，除表示“证明……为正当，有理由，有权利”外，还可表示“保证，担保”。作“保证，担保”解时，较常用guarantee。
- Is this material warranted (to be) pure silk?
这种料子能保证是纯真丝的吗？ - Can you warrant him (to be) an honest and reliable man?
你能担保他是一个诚实可信的人吗？ - I warrant (you) that the TV set is of fine quality.(也可用assure you)
我(向你)保证这台电视机的质量是上乘的。 - If you can warrant/guarantee the authenticity of the painting, I'll take it.
如果你能担保这幅画是真迹，我就买下它。
(7) ①commit也可表示“承诺，答应，保证”之意，常指使自己受到某种约束、承担某种责任(做某事或支持某事)；此外还有“调配……供使用，拨出”的意思。
- The committee has committed more funds to improving the environment.
委员会承诺拨出更多的资金来改善环境。 - She has been committed to going to the U.S. to live with her daughter.
她答应到美国与她的女儿一起生活。
②commit可接反身代词，表示“承担义务，支持，许诺”。
- He has committed himself to assume the research work.
他许诺来承担这项研究工作。 - The municipal government committed itself to appropriate/appropriating ten million dollars for the improvement of the communications facilities.
市政府许诺拨出一千万美元以改善通信设施。
(8) ①vouch表示“保证，为……担保”，指为某人的能力或人格、某事的真实性负责。该词多用作不及物动词，常与介词for连用。
- I'm thinking of getting a loan from the bank — are you willing to vouch for my ability to pay?
我正在考虑从银行贷款——你愿为我的偿付能力作担保吗？
②vouch有时可接that从句。
- I can vouch (for it) that he cherishes no intention to leave/of leaving our company.
我敢保证他根本没有离开我们公司的打算。
(9) vow表示“发誓、起誓(做某事)”，常用不定式或that从句。
- The young couple vowed to love each other throughout eternity.(The young couple vowed eternal love.)
这对年轻夫妻发誓永远相爱。 - The young man vowed that he would avenge his father's death on the murderer.
这个年轻人发誓他一定要向谋杀他父亲的凶手报仇。
(10) ①assure可表示“断然地说，有信心地说，保证”。
- I assure you (that ) carrying out the plan will be out of question.
我向你保证这项计划将得以顺利实施。
②assure还作“使……相信；向……保证”解。
- He tried to assure me there was no need to be worried about his safety in Washington.
他努力使我相信根本没必要担心他在华盛顿的安全。 - He assured me of his readiness to help.
他向我保证他很乐于帮我。
③assure又作“保证得到，保证有”解，此时可与ensure , guarantee, warrant互换。
- Nothing in the world, neither wealth nor high position, can assure/guarantee (a man) permanent happiness.
世界上没有任何一样东西，无论是财富还是显赫的地位，能确保一个人永远幸福。
(11) ensure意为“使……一定做到，保证(有)”。
- These documents ensure (to) you the authority you need in directing the project.
这些文件会确保你得到指挥这项工程所需的权威。 - Can you ensure that the goods we urgently need will be delivered to us in time?
你能保证我们急需的这些货物能及时发送给我们吗？ - To ensure getting a good seat, do come earlier.
为确保得到一个好座位，一定要一些早来。
