I'm Alice Bryant. The words if and whether are conjunctions that connect two or more sentences or clauses.

In part one of this program, I talked about when to use the word.

Whether on today's program I will talk about when if must be used and when the two words are interchangeable, we use, if in conditional sentences, we cannot use whether a conditional sentence is one that presents a condition and a result.

In other words, when a happens be happens, here's an example.

If I won the lottery, I would buy a house in this sentence.

If I won, the lottery is the condition, and I would buy a house is the result next?

Let's talk about two situations in which "if" and "whether" are interchangeable. When reporting yes or no questions, we can use "if" or "whether". 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, listen to the examples.

Can you tell me if the train is coming soon?

Can you tell me whether the train is coming soon as discussed in Part one.

There are some exceptions.

You can learn more about them in that program, and that's everyday grammar.