In my understanding so far, the first sentence represents a condition "I can't open the webpage without a browser."
The second means the webpage can not be opened, no conditions.
Please correct me!
Many natives are firmly convinced that "if" and "whether" are interchangeable, which is not true. Some natives only use "if," which is wrong. Word to the wise: there are lots and lots of native English speakers out there; not all of them are geniuses. Some of them are pretty ... uh ... but I digress.
A wether is a castrated male sheep. The word you have in mind is always spelled with an "h" following the "w."
Consider the following:
The mezzo will sing if she feels up to it.
Or:
Hopefully the mezzo will sing for us tonight. Go and find out whether she feels up to it.
You can't use "whether" instead of "if" in the first example.
You could use "if" instead of "whether" in the second one, and many people would, but it doesn't sound quite right to a native ear that is genuinely attuned to the ... uh ... polyphony, for lack of a better word ... of the English language.
The construction "whether ... or not" is used to indicate that a certain condition is not relevant to the issue.
You can't drive from Canada to Australia whether you have a passport of not.
In this case, while you do need a passport to travel from Canada to Australia, the major impediment is the lack of a bridge across the Pacific ocean, and having a passport does not remove that impediment.
So in the original sentence, there is some impediment to opening the page, other than the lack of a web browser.
So essentially the "whether ... or not" construction is saying that the condition is question is irrelevant. Thus it is not really a conditional construct but an absolute one.
"Z, whether X or Y" or "Whether X or Y, Z" means that Z is the same if X or Y is true.
Whether the store has "Call of Duty Black Ops" or "Madden 16", I'm buying a PS4 game.
In the above example, Y reuses X's verb, and it's not necessary to repeat it, but X and Y can contain their own verbs.
Whether she hates me or she loves me, I still have to go to the party.
Typically X will have a verb, if it doesn't, the meaning will be "X is" or "there is":
Whether rain or snow, the post office delivers mail.
Whether sick or well, she was at work every day.
Plain old whether X with no Y has an implied "or not X" on the end of it. Usually including the "or not [X]" will sound/read as repetitive but can be included for emphasis.
I don't know whether she'll go = I don't know whether she'll go or she won't go.
So whether is not really a conditional, it's saying something is going to happen regardless of two or more possible outcomes. It's the opposite of a conditional.
