Hi again.Welcome back to www. engvid. com.My name's Adam.Welcome again.
嗨。欢迎来到www.engvid.com。我是Adam。再次欢迎。
Today's lesson is a grammar lesson, and this is a question that I am asked often.
今天的课程是语法课，也是我经常问的一个问题。
What is the difference between "if" and "whether"? Okay?
"if" 和 "whether" 有什么区别？
It's a very good question, pretty simple, straightforward, but we're going to look at both of these in relation to each other.
这是一个非常好的问题，坦白的说，它非常简单，但是我们要看一下它们彼此有哪些联系。
First of all, let's make sure everybody understands "whether" is not spelled the same as "weather", like sunny, raining.
首先，让我们确保每个人都明白 “whether” 和 “weather” 的拼法是不一样的，就像晴天，雨天。
This is about rain, sun, snow, wind, temperature.This is similar to "if", it's about having choices. Okay?
这是关于雨，太阳，雪，风，温度；这跟 “if” 是相似的，if 是与选择相关的。对吧？
So, in some situations, "if" and "whether" are interchangeable, but the best way to not make a mistake, not to mix them up in the wrong context is to always use "if" for conditionals.
所以，在某些情况下，”if”和”whether”是可以互换使用的，但为了在错误的语境下不出错，不把他们弄混，最好的方式是总是用 “if” 来表示条件；
Always use "whether" when you're talking about two alternatives, two choices. Okay?
当你谈论两个选项，两个选择的时候，总是用”whether”。好吗？
You'll see what I mean.When they can be interchanged.
你马上就会明白我是什么意思。它们可以互相替换的情况。
First of all, when they are used as noun clauses, means they can be the object or the subject of a sentence, they can mean the same thing.
首先，当它们被用于名词性从句时，意味着它们可以作为句子的宾语或主语，它们可以表达一样的东西。
But again, avoid using them the same if you don't want to make mistakes.
但再说一遍，如果你不想犯错误，不要同样地使用它们。
"Do you know if Dan is coming?"Do you know what?If Dan is coming.
“你知道 Dan 是否要来吗？”你知道什么？Dan是否要来。
"Do you know whether Dan is coming?"In this case, they basically mean the same thing.Yes or no: is he coming or is he not coming?
“你知道 Dan 是否要来吗？”在这种情况下，它们基本上意味着同样的事情。是或不是：他要来吗或他不会来吗？
You could add the "or not?" here: "Do you know whether Dan is coming or not?"
你可以把 "or not？"加在这里："Do you know whether Dan is coming or not？"
But the word "whether" already gives you a choice between yes or no in this particular case, so this is not necessary.
但是在这种特定的情况下，"whether" 已经在是或不是中给出了选择，所以这是不需要的。
It's understood. Okay?Now, let's look at these two sentences: "I don't know if the exam is on Friday or Saturday."
这是约定俗成的。明白吗？现在，让我们来看一下这两个句子：“我不知道考试是在周五还是在周六。”
"I don't know whether the exam is on Friday or Saturday."So here, we're looking directly at a choice.
“我不知道是否在周五或周六考试。”在这里，我们直接看出了一个选择。
When I use "whether": "I don't know whether the exam is on Friday or Saturday."
当我使用 "whether"：“我不知道考试是在周五还是在周六。”
So again, you have two options when you look at "whether".Friday is one option, Saturday is another option.
那么再说一次，当你看到 "whether" 的时候你有两个选择。星期五是一个选择，星期六是另一个选择。
The problem here is if you use "if", "if" is not limited to two options.
问题在于当你使用 "if" 时，"if" 不仅仅只有两个选择。
"I don't know if the exam is on Friday or Saturday, or if it's next week sometime."
“我不知道考试是在周五还是在周六，还是在下周的某个时间。”
So here, although they seem to mean the same thing, the "if" gives you other options that the "whether" doesn't.
那么这样的话，尽管他们意味着同样的事情，"if" 给了你其他的选择，而 "whether" 却没有。
"Whether": one, two."If": one, two, or something completely different.
"Whether"：一个，两个选择。"If"：一个，两个，或其他完全不同的东西。
So if you want to avoid making this mistake, use "whether" for the choices, use...Save "if" for when you have your conditional sentence.
所以如果你想避免犯错，用 "whether" 来表示选择，把 "if" 用于条件语句。
Now, what is a conditional sentence?A conditional sentence is using "if" as an adverb clause.
现在，什么是条件句？条件句是用 if 引导的状语从句。
There's a condition.If "A" happens, "B" will happen. Okay?
它是有条件的。如果 “A” 发生，则 “B” 发生。对吧？
One thing needs to happen for the second thing to happen, that's the condition.
一件事情的发生需要另一件事情的发生，这就是条件。
So: "Let me know", oh, sorry.I forgot this word, here."Let me know if you're coming."
那么："Let me know"，噢，抱歉。我这里漏了一个词。“如果你要来，通知我。”
"Let me know whether you're coming."In this case, they're both okay."Let me know whether you're coming or not."
“通知我你是否会来。”在这个情况下，这两个句子都是可以的。“通知我你来还是不来。”
Now, what's the difference between: "Let me know if you're coming", "Let me know whether you're coming or not"?
现在，这三个句子有什么不同："Let me know if you're coming"，"Let me know whether you're coming or not"？
If you are coming, yes, let me know.This is a conditional.If this is true, do this."Let me know whether you're coming or not."
如果你要来，通知我。这是一个条件。如果这是真的，这么做。“让我知道你是否会来。”
If you're coming, let me know; if you're not coming, let me know.So in this case, both apply. Okay?
如果你要来的话，通知我；如果你不来的话，通知我。所以在这种情况下，两者都是条件。对吧？
So, again, use this to...The condition.This is the condition, this is the result.
那么再说一次，这种情况用于...条件句。这是条件，这是结果。
Here, this is going to happen regardless.So we're going to look at this in a second in more detail. Okay?
而这边，无论如何，这都是将要发生的。那么我们接下来看一下更多的细节。好吗？
"I'll come over if you want me to."If you want it, I will do it; if you don't want it, I will not do it.
“如果你想要我来的话，我就顺便过来。”如果你想要的话，我将要去做它；如果你不想要的话我将不会做。
So this is the condition.If you want me to, I'll come over.This is the condition, this is the result.
所以这是一个条件。如果你想的话，我将顺便过来。这是条件，这是结果。
So your best option is to always use "if" with conditionals, use "whether" to talk about two alternatives.
所以你最好总是用 "if" 搭配条件句，用 "whether" 来谈论两个选择。
Now, the other common use of "whether" is to mean "regardless".
现在，"whether" 另一个普遍的用法是表示 “无论，不管”。
Doesn't matter what happens, regardless of the situation, here's what I want you to do."I'm coming over whether you like it or not."
不管发生了什么，无论是什么情况，这是我想让你做的。“无论你喜欢或是不喜欢，我都会过来。”
Okay. "Whether you like it or not" means if you like it, I'm coming over;
好。"Whether you like it or not" 意思是如果你同意，我会过来；
if you don't like it, too bad, I'm coming over.So this verb is going to happen regardless of this situation. Okay?
如果你不同意，很遗憾，我还是会过来。所以这个动作是无论是什么情况都会发生的。对吧？
So that's when we must also use the "or not".Remember here, I said "or not" can come out because it's understood here.
所以这就是我们必须使用 "or not" 的时候。记住这点，我说过这里不需要 "or not" 因为这是约定俗成的。
Here are your two options.Here, it's not about options.Here, it's about saying something is regardless.
这里是说有两个选择。而这里，它不是关于选择。这里是在说无论如何都会做某事。
Doesn't matter what you like, what you don't like - I'm coming over. Okay?
无论你喜欢还是不喜欢，我将会过去。对吧？
"I'm coming over if you like it", it means: you like it, I'm coming; you don't like it, I'm not coming. Okay?
"I'm coming over if you like it"，意思是：如果你喜欢，我就过去；你不喜欢，我就不会过去。对吧？
So: "whether", to talk about regardless, you must have the "or not".To give the options, you don't need the "or not".
所以，"whether"来描述regardless时，你必须有"or not"。当表示给出选择时，你不需要 "or not"。
If, in a noun clause-means the situation-is the object of "know".Know what?If he is coming.Yes or no.Here, it's a conditional.
If，在一个名词性从句里，意思这种情况是 "know" 的宾语。知道什么？他是否来？来还是不来。这里，这是一个条件句。
So first of all, you must understand: is it a noun clause object or is it an adverb clause condition?
所以，首先你必须了解：它是名词性从句的宾语还是状语从句的条件？

So, to avoid making mistakes, especially in written English: use "if" for conditionals, use "whether" for alternatives or to mean "regardless". Okay?
那么，为了避免犯错误，尤其是在书面英语中：用 "if" 来表示条件，用 "whether" 来表示选择或表示 “不论，不管”。好吗？
It's a little bit tricky, but when you see more examples, it will become much clearer.So if you want to see more examples, come to www. engvid. com.
它有点复杂，但是你多看一些例子后，它会清楚很多。如果你想看更多的例子，登录www.engvid.com。
There's a quiz there that will test your understanding of this.Ask any questions you have on the comments section.
那有一个测验来测试你对这些内容的理解。如果有问题的话可以在评论区提出来。
Don't forget to subscribe to my YouTube channel.Come back.I'll see you again.Bye.
不要忘记订阅我的YouTube频道。下次也要继续收看。我们会再见的。拜。