Whether Vs If. To express an alternative we can use or not with if and whether. The formal rule is to use if when you have a conditional sentence and whether when you are showing that two alternatives are possible.
With whether we can use or not immediately after whether or in end position. The formal rule is to use if when you have a conditional sentence and whether when you are showing that two alternatives are possible. Most of the time when the word whether is used the word or also is used.
Whether is used when the sentence is discussing a choice or two alternatives and is used before an infinitive using the word to and after a preposition.
What is the difference between if and whether. Remember if is used when the sentence is conditional. Use if when you have a conditional sentence. The formal rule is to use if when you have a conditional sentence and whether when you are showing that two alternatives are possible.