Hypothetical situations are situations that we imagine. There are specific English grammar structures, phrases and forms to express hypothetical situations. Here are some examples of some hypothetical situations using a wide variety of forms.
假设情景是我们想象的情景。有特定的英语语法结构、短语和形式来表达假设情况。下面是一些使用各种形式表示假设情况的例子。

They would invest in R & D if they had the capital. - Conditional Form

If only we had enough time to take a vacation. - Partial conditional form / set phrase 'if only'
如果我们有足够的时间去度假就好了。-部分条件形式/固定短语“if only”

It's time we improved our sales. - Set phrase 'it's time'
是时候我们该提高销售量了。-固定短语“It's time”

I wish he lived here. - Verb 'wish' to express a desire
我希望他住在这里。-表示愿望的动词“wish”

English uses conditional forms to express hypothetical situations.
英语使用条件形式来表达假设情况。

If they have time, they will come to the meeting.
如果他们有时间，他们会来开会的。

They would invest in R & D if they had the capital.
如果他们有资本，他们会投资于研发。

If Jack had taken the job, he wouldn’t have been satisfied.
如果杰克接受了这项工作，他就不会自满了。

There are also a number of other forms to express hypothetical situations in English.
还有许多其他形式可以用英语表达假设情况。

If Only
要是...就好了

‘If only’ takes the same verb forms as ‘wish’. This form is used as a means of stressing the importance of the wish or hypothetical situation. The form is often also used with an exclamation point.
“if only”采用与“wish”相同的动词形式。这种形式被用来强调愿望或假设情况的重要性。这种形式也常加上感叹号。

If only there were more job opportunities!
要是有更多的工作机会就好了！

If only Mary could work for us.
要是玛丽能为我们工作就好了。

If only our friends had time to take a vacation with us in Hawaii.
如果我们的朋友有时间和我们一起去夏威夷度假就好了。

‘If only’ can also be used with ‘would / wouldn’t’ to criticize another person.
“if only”还可以与“would/wouldn't”一起用于批判另一个人。

If only the boss would listen to my proposals!
要是老板听我的建议就好了！

If only Jeff would consider hiring Peter.
要是杰夫考虑雇用彼得就好了。

If only Susan wouldn't spend so much time online.
要是苏珊不花那么多时间上网就好了。

'If only' statements generally imply some sort of solution. Here are some of the example sentences with the implied solutions provided.
“if only”通常意味着某种解决方案。下面是一些带有隐含解决方案的例句。

If only there were more job opportunities! - I could find a better job.
要是有更多的工作机会就好了！-我可以找到一份更好的工作。

If only Jeff would consider hiring Peter. - He's the perfect person for the job.
要是杰夫考虑雇用彼得就好了。-他是这份工作的最佳人选。

If only Susan wouldn't spend so much time online. - It can't be healthy for her.
要是苏珊不花那么多时间上网就好了。-对她来说不这样是不健康的。

It’s Time
该...的时候到了

Use ‘it’s time’ with the past simple to talk about an action which finally is taking place, or should take place soon. It always refers to an action or state that should have taken place before the moment of speaking.
用“It's time”和一般过去时讨论一个正在发生，或应该很快发生的活动。它是指一种应该在说话之前就发生的行为或状态。

It’s time you began working on your own.
现在是你开始自己工作的时候了。

It's time we changed to a new internet service provider.
我们该换个新的互联网服务提供商了。

It's time they grew up!
他们该长大了！

Variations on ‘It’s Time’
关于‘It’s Time’的时间变体

Here are some common variations on ‘it’s time’ which have the same meaning:
以下是一些常见的“时间”变体，它们具有相同的含义：

It’s about time…
该...的时间到了

It’s high time…
该...的时间到了

It’s high time she took a shower!
她该洗澡了！

It's about time we left for the meeting.
我们该去开会了。

Would Rather
宁愿

There are two uses of ‘would rather’ to express hypothetical situations:
“would rather”表示假设情况有两种用法：

Would Rather + Base Form of Verb
Would Rather + 动词原形

Use ‘would rather’ + the base form of a verb to talk about our preferences in the present or the future:
使用动词的基本形式“would will”+来讨论我们现在或将来的偏好：

He’d rather his employees work less overtime.
他宁可让他的雇员少加班。

I'd rather leave now.
我宁愿现在就走。

Jack would rather take a different approach.
杰克宁愿采取不同的方法。

In each of these cases, the phrase with 'would rather' shows that another action is taking place than the preferred action of the subject of the sentence.
在每一种情况下，带有“would rather”的短语都表示正在进行另一个动作，而不是句子主语的首选动作。

Would Rather + Past Perfect
Would Rather + 过去完成时

Use ‘would rather’ + past perfect to express hypothetical situations in the past:
使用‘would rather’ +过去完成时表示过去的假设情况：

They’d rather they hadn’t spent so much on the marketing campaign.
他们宁愿在营销活动上不花那么多钱。

Mary would rather she had chosen a different position.
玛丽宁愿选择一个不同的职位。

Wish
希望

We use ‘wish’ to talk about situations we’d like to change. In this sense, ‘wish’ is very similar to the second or third conditionals because it poses an imaginary situation.
我们用“wish”来谈论我们想要改变的情况。在这个意义上，“wish”与第二或第三个条件非常相似，因为它构成了一个假想的情况。

Wish for Present Situations
对于现在的情况的希望

When we are wishing for a change in a present situation, we use ‘wish’ plus the simple past.
当我们希望改变现状时，我们用“wish”加上一般过去时。

The director wishes he could attend the presentation.
主任希望他能参加发布会。

They wish he concentrated more on his work and less on his hobbies.
他们希望他多关注工作，少关注业余爱好。

Wish for Past Situations
对于过去情况的希望

When we are speaking about a past situation in a present moment, we use ‘wish’ plus the past perfect.
当我们现在谈论过去的情况时，我们使用“wish”加上过去完成时。

Janet wishes she had applied for a new position.
珍妮特希望她申请了一个新职位。

We wish you had seen the opportunity in time.
我们希望你能及时看到这个机会。