外教微课是为大家推出的系列网络外教课程。每集配备一个10分钟左右的视频，常听多看，锻炼口语听力，提升语言能力。Learn how to use "if" and "whether" properly in English. Whether you like it or not, "if" and "whether" are not always interchangeable. In fact, if you use the wrong word, it can change the entire meaning of your sentence.
In this lesson, we will review the uses of the two words and see how to use them in a way that will reduce confusion and clarify your ideas. How can you be sure whether to use "if" or "whether" in the proper context? Watch the lesson, and find out!
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TRANSCRIPT
Hi again. Welcome back to www.engvid.com. My name's Adam. Welcome again. Today's lesson is a grammar lesson, and this is a question that I am asked often. What is the difference between "if" and "whether"? Okay? It's a very good question. It's pretty simple, straightforward, but we're going to look at both of these in relation to each other.
First of all, let's make sure everybody understands "whether" is not spelled the same as "weather", like sunny, raining. This is about rain, sun, snow, wind, temperature; this is similar to "if", it's about having choices. Okay?
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; always use "whether" when you're talking about two alternatives, two choices. Okay? You'll see what I mean.
When they can be interchanged. 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. But again, avoid using them the same if you don't want to make mistakes. "Do you know if Dan is coming?" Do you know what? If Dan is coming. "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? You could add the "or not?" here: "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. It's understood. Okay?
Now, let's look at these two sentences: "I don't know if the exam is on Friday or Saturday.", "I don't know whether the exam is on Friday or Saturday." So here, we're looking directly at a choice. When I use "whether": "I don't know whether the exam is on Friday or Saturday." So again, you have two options when you look at "whether". Friday is one option, Saturday is another option. The problem here is if you use "if", "if" is not limited to two options. "I don't know if the exam is on Friday or Saturday, or if it's next week sometime." So here, although they seem to mean the same thing, the "if" gives you other options that the "whether" doesn't. "Whether": one, two. "If": one, two, or something completely different.
So if you want to avoid making this mistake, use "whether" for the choices, use... Save "if" for when you have your conditional sentence. Now, what is a conditional sentence? A conditional sentence is using "if" as an adverb clause. There's a condition. If "A" happens, "B" will happen. Okay? One thing needs to happen for the second thing to happen, that's the condition. So: "Let me know", oh, sorry. I forgot this word, here. "Let me know if you're coming.", "Let me know whether you're coming." In this case, they're both okay. "Let me know whether you're coming or not."
Now, what's the difference between: "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." If you're coming, let me know; if you're not coming, let me know. So in this case, both apply. Okay? So, again, use this to... The condition. This is the condition, this is the result. Here, this is going to happen regardless. So we're going to look at this in a second in more detail. Okay?
"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. So this is the condition. If you want me to, I'll come over. This is the condition, this is the result. So your best option is to always use "if" with conditionals, use "whether" to talk about two alternatives.
Now, the other common use of "whether" is to mean "regardless". 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." Okay. "Whether you like it or not" means if you like it, I'm coming over; if you don't like it, too bad, I'm coming over. So this verb is going to happen regardless of this situation.
Okay? 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. Here are your two options. Here, it's not about options. Here, it's about saying something is regardless. Doesn't matter what you like, what you don't like - I'm coming over. Okay? "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? So: "whether", to talk about regardless, you must have the "or not". To give the options, you don't need the "or not". If, in a noun clause-means this situation-is the object of "know". Know what? If he is coming. Yes or no. Here, it's a conditional.
So first of all, you must understand: is it a noun clause object or is it an adverb clause condition? So, to avoid making mistakes, especially in written English: use "if" for conditionals, use "whether" for alternatives or to mean "regardless". Okay? 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. There's a quiz there that will test your understanding of this. Ask any questions you have on the comments section. Don't forget to subscribe to my YouTube channel. Come back. I'll see you again. Bye.网络资源，仅供学习交流