Word Choice: If vs. Whether

Word are tricky things. Take ‘if’ and ‘whether’, for example. Sometimes these terms are interchangeable. As such, you can use either word in these cases without worrying which is ‘correct’.

However, these words are not interchangeable in every situation. In these cases, picking the wrong term could be confusing (or even change the meaning of a sentence completely). So, to help you avoid errors, we’ve prepared a quick guide to how these words should be used.

Yes/No Questions (‘Whether’ or ‘If’)

‘Whether’ and ‘if’ are interchangeable when referring to something that could be posed as a yes/no question. For example, if the question were ‘Am I going to be late?’, we could say either:

I don’t know whether I’ll be late. ✓

I don’t know if I’ll be late. ✓

Both terms express uncertainty, so either can be used (although ‘whether’ is more formal).

Conditional Statements (‘If’ Only)

If you’re making a conditional statement, you need to use the word ‘if’:

If I leave soon, I will get there on time. ✓

Whether I leave soon, I will get there on time. ✗

We can’t use ‘whether’ here because ‘whether’ always implies a choice between at least two options. Here, by comparison, we’re simply setting out a condition and a consequence.

Choices (‘Whether’ Only)

As mentioned above, ‘whether’ implies a choice between two or more things:

I can’t decide whether I should go today or tomorrow.

Here, ‘whether’ shows that the speaker has two options (i.e. going today or tomorrow). If we were to use ‘if’ in the same sentence, this would be less clear:

I can’t decide if I should go today or tomorrow.

This isn’t ungrammatical, but it is ambiguous. Essentially, we can’t tell whether the speaker is expressing a choice between two things (i.e. going today or tomorrow) or making a conditional statement (i.e. whether to go at all).

As such, it is best to use ‘whether’ for any situation that involves multiple possibilities, as it is typically clearer and more formal.