If and Whether, Part 2

Today, we continue our discussion about "if" and "whether." Both words are conjunctions that can sometimes be used in place of each other.

The word "whether" shows that there are two possibilities or choices for something. And sometimes the word "if" shares this meaning. For instance, you can say, "Please find out if my books have arrived" or "Please find out whether my books have arrived."

Other times, only one of the words can be used.

In Part 1 of this program, we talked about when "whether" must be used. On today's program, Part 2, we will talk about when "if" must be used. I will also explain when the two words are interchangeable. And lastly, I will tell you an easy way to remember which to choose.

Use ‘if' in conditionals

Let me start by talking about conditionals.

Conditional sentences present a condition and a result. In other words, when A happens, B happens.

We use "if" to express a condition. We cannot use "whether." Listen to this example:

If it rains, we will get wet.

In this sentence, "If it rains" is the condition and "we will get wet" is the result.

Here is another example:

I would buy a car if I won the lottery.

In this example, the condition is "if I won the lottery." The result is "I would buy a car." Notice that the condition comes in the second half of the sentence. This change in position does not affect the meaning.

Again, the word "whether" cannot be used to express conditions.

Use either word

Next, let's talk about when "if" and "whether" are interchangeable. That means either word can be used with no change in meaning.

When reporting yes or no questions, we can use "if" or "whether." Reported questions involve telling someone what another person has asked. Listen to two statements to see what I mean:

He asked if I listen to music every night.

He asked whether I listen to music every night.

We can also use "if" or "whether" when asking indirect yes or no questions. An indirect question is one that is worded more politely than a direct question. Listen to the examples:

Can you tell me if the train is coming soon?

Can you tell me whether the train is coming soon?

We can also use "if" or "whether" in statements to express doubt about which of two possibilities is true. In these cases, the word "or" is used. Listen to these statements:

We are unsure if the deadline is Wednesday or Friday.

We are unsure whether the deadline is Wednesday or Friday.

As discussed in Part 1, there are some exceptions. For example, use only "whether" after prepositions and before infinitive verbs. You can read more about the exceptions in that program.

Understand noun clauses

Now, let's talk a little about noun clauses.

In all of today's example sentences (except the conditionals), the words "if" and "whether" introduce noun clauses.

A clause is a part of a sentence with its own subject and verb. Noun clauses act like nouns in sentences.

Let's take a closer look at an example:

We are unsure whether the deadline is Wednesday or Friday.

In this example, the noun clause is "whether the deadline is Wednesday or Friday." Notice that the word "whether" introduces the noun clause. And the subject and verb of that clause are "the deadline" and "is."

You can learn more about noun clauses on earlier Everyday Grammar programs.

How to remember

Well, that was a lot of information! So, how can you remember it all? The good news is that you do not have to.

If you are ever in doubt about which word to choose, you can keep it simple. The best way to avoid confusion is this: Use "if" for conditionals and use "whether" when talking about two possibilities or choices.

I'm Alice Bryant.

Alice Bryant wrote this story for Learning English. Caty Weaver was the editor.