ought

来自古英语ahte,拥有的，所有的，来自agan的过去分词，拥有，所有，词源同own,owe.后词义由拥有的引申为有义务去支付或偿还，并最终在语法上演变成虚拟情态动词。

ought

ought: [OE] Ought began life as the past tense of owe, but the two have diverged widely over the centuries. The Old English ancestor of owe was āgan, and its past form was āhte. This originally shared all the meanings of its parent verb, of course, and continued to do so well into the 17th century (‘He said this other day, you ought him a thousand pound’, Shakespeare, 1 Henry IV 1596). Indeed, it survived dialectally until comparatively recently. But steadily since the 1600s its role as a quasi-modal auxiliary verb, denoting ‘obligation’, has come to the fore.
=> owe

ought (v.)

Old English ahte "owned, possessed," past tense of agan "to own, possess, owe" (see owe). As a past tense of owe, it shared in that word's evolution and meant at times in Middle English "possessed" and "under obligation to pay." It has been detached from owe since 17c., though he aught me ten pounds is recorded as active in East Anglian dialect from c. 1825. As an auxiliary verb expressing duty or obligation (late 12c., the main modern use), it represents the past subjunctive.

ought (n.)

"zero, cipher," 1844, probably a misdivision of a nought (see nought; for misdivision, see N); meaning probably influenced by aught "anything."

1. The money to build the power station ought to have been sufficient.

建设电站的资金本该足够了。

2. I think you ought to give football a rest for a time.

我认为你应该暂时停止踢足球。

3. You know, we really ought to get another car.

要知道，我们真的应该换一辆车了。

4. I felt I ought to show my face at her father's funeral.

我觉得我应该去参加她父亲的葬礼。

5. You ought to be ashamed of yourselves. You've created this problem.

你们应该感到惭愧，都是你们惹的祸。