[Grammar] Help from native speakers

[HUFS1999]

Yesterday I got a student who asked me, "Does it make any difference between "if" and "whether" in this sentence: "I will go to the dentist whether I am in pain or not."

For me, I can`t see any difference between them except just my feeling says "whether" sounds more natural.

What do u think?

Thank you in advance.

[ohmyrichard]

Originally Posted by HUFS1999

Yesterday I got a student who asked me, "Does it make any difference between "if" and "whether" in this sentence: "I will go to the dentist whether I am in pain or not."

For me, I can`t see any difference between them except just my feeling says "whether" sounds more natural.

What do u think?

Thank you in advance.

Although I'm not a native, I can answer your question. We can add a clause containing "whether" and "or not" to a sentence to indicate that something is true in any of the circumstances we mention. Your sentence is a good example. This remark is a decision. It may be uttered to indicate the speaker's determination to have his or her decayed tooth pulled out at the dentist's. In this case, "whether" cannot be replaced by "if". Another example could be "He's going to buy a house whether he gets married or not."
Still another example is "I will give an answer to your question whether you doubt its correctness or not."
By the way, may I know which grade you teach?

[serega kobrin]

As far as I understood "or not" implies "whether"
Or you can give opposite example

[Soup]

Originally Posted by HUFS1999

Yesterday I got a student who asked me, "Does it make any difference between "if" and "whether" in this sentence: "I will go to the dentist whether I am in pain or not."

For me, I can`t see any difference between them except just my feeling says "whether" sounds more natural.

What do u think?

Thank you in advance.

See also here Writer's Block - Writing Tips - "Whether" Vs. "If" and here GMAT Grammar: "Whether" vs "If".