English as a Second Language/question
When we have 2 alternatives in a sentence we use whether, does it mean that using if is incorrect.how about if we have 1 and 3 alternative?can explain me using some example?
Are these sentences correct?(I have read a lot of pages on the net about if and whether but I still have doubt about them.)
I don't know whether he stayed at home.
I don't know if he stayed at home.
I don't know if he will eat that food.
Usually when you have two alternatives you should use "whether", but it' not incorrect to use "if" either; "whether" is more common.
A few examples:
I don't know whether he's going to come to work today. (the 2nd alternative here is that he won't how up to work, and while it's not written in the sentence, it's implied)
I don't know if he's going to come to work today. (this is also correct)
I don't know if he's going to visit us in May or June. (this implies that it's also possible that he won't visit at all)
I don't know whether he's going to visit us in May or June. (here the implication is that he's coming either in May or in June, but he's definitely coming).
I would like to know if/whether he likes cats or dogs. (here you have two alternatives and you can use both whether or if, but again you'll find "whether" to be more common)
Let me know whether/if you're able to join us for drinks after work. (here the second alternative is implied, so again using "whether" is more common)
I don't know whether he stayed at home. >>> incomplete
I don't know if he stayed at home. >>> correct
I don't know if he will eat that food. >>> correct
Only none of the examples you provided have anything to do with the rule you asked me about.
I assume you'll follow up with more details here as I'm not sure I addressed your question entirely.
Please keep in mind that the more detailed your question, and the more context you provide, the better I can assist you.