I saw a personal email message the other day that illustrates well the difference between “if” and “whether” — two conjunctions that are not synonyms.

Problem:
Writing the conjunction “if” in place of “whether” — even in informal writing — can confuse readers.

Explanation:
I wrote about these two conjunctions back in January, but I have since found a simple example that illustrates why “if” is dangerous as a substitute for “whether”.

The example appeared in an email message from a woman who was arranging a party:

• “Please let me know if you’ll be coming to my party.”

Changing the order of the sentence, we get:

• “If you’ll be coming to my party, then please let me know.”

This implies that the message writer was not asking to hear from message readers who would not be attending her party.

However, I talked to the message writer and learned that she wanted to hear from everyone who got her email message. This would ensure that she had confirmation either way — “Yes, I’ll be coming to your party.” or “No, I won’t be coming to your party.” — from each of the message recipients.

The message writer should have used “whether” instead of “if” in her sentence to ensure that she got confirmation either way (“yay” or “nay”):

• “Please let me know whether you’ll be coming to my party.”

Solution:
Be careful with using “if” as a substitute for “whether” in whatever you write — even personal email messages. Otherwise, you might not get the results that you desire.