Is 'If worse comes to worst' correct?

Anything that is commonly used in standard English is correct.
CB

.
And good evening from Yokohama!

The grammar is fine. Here's what the Columbia Guide has to say about the saying:

if (when) worse (worst) come(s) to worst

Thank you very much again, Mister Micawber.

Not exactly. If you mean, anything that is commonly used in standard English is acceptable (i.e. able to be used without fear of mis-comprehension or ridicule), then perhaps. But it seems that the questioner was asking whether the phrase was 'grammatically correct', which has a different meaning. It's clear that the questioner knows the phrase to be acceptable and, probably, commonly used. Howeve

.
I concur with CB's comment. It amounts to the same thing.'
.

You can use : if worst comes to worst OR if worse comes to worst

Both are correct

I was just wondering this myself when I came across your question. Apparently both are perfectly acceptable (though I, myself, prefer "Worse comes to worst"). Here's a link to a great article that explains it:

http://www.nytimes.com/2011/02/06/magazine/06FOB-onlanguage-t.html

Anonymous. Here's a link to a great article that explains it:http://www.nytimes.com/2011/02/06/magazine/06FOB-onlanguage-t.html?_r=1

Good link! To quote from it:

The earliest version of the idiom is in the form “if the worst com

I disagree, and here is why, Just because something is often used in the English language does not make it correct. Take for example the phrase : "I could care less", it is incorrectly used to signify the fact that you don;t care at all. In fact it implies that you do care a little and there is room for you to care a little less.The correct use should be " I COULDN'T care less" implying that you

AnonymousTherefore the term "If (when) worse comes to worst" is the only way to properly use it,

Did you bother to follow this link, http://www.nytimes.com/2011/02/06/magazine/06FOB-onlanguage-t.html?_r=1, and read the article?