Difference between “while” and “whilst” [duplicate]

Question

Possible Duplicate:
What is the correct usage of “while” and “whilst”?

In terms of construction of sentences, can the two words while and whilst be used interchangeably?

Answer 1

Garner in Modern American Usage has a good entry on this. He says:

whilst, though correct BrE, is virtually obsolete in AmE and reeks of pretension in the work of American writer.
[...]
Like its sibiling while, it may be used for although or whereas. But again, this isn't good usage in AmE.

As NOAD say whiles is archaic form of while.

So, whiles and whilst might be interchangeable, but with the above warnings.

Answer 2

The entry at World Wide Words says that while and whilst are forms of the same word. He notes:

Both while and whilst are ancient, though while is older. There’s no difference in meaning between them. For reasons that aren’t clear, whilst has survived in British English but has died out in the US. However, in Britain it is considered to be a more formal and literary word than its counterpart.

How did it come to be this way? Like amid and amidst, he adds:

In both cases, the form ending in -st actually contains the -s of the genitive ending (which we still have today, though usually written as ’s, of course). In Middle English, this was often added to words used as adverbs (as while became whiles, which often turned up in the compound adverbs somewhiles and otherwhiles). What seems to have happened is that a -t was later added in the south of England through confusion with the superlative ending -st (as in gentlest).

So you can use them interchangeably, but note that whilst reads as more formal. In American English, it appears extremely rarely so be aware of the audience you're addressing when you make this choice.