'else' is archaic, rather than wrong. A quote from Shakespeare's Cybeline: If Caesar can hide the sun from us with a blanket, or put the moon in his

'else' is archaic, rather than wrong. A quote from Shakespeare's Cybeline: If Caesar can hide the sun from us with a blanket, or put the moon in his pocket, we will pay him tribute for light; else, sir, no more tribute, pray you now. If / else is perfectly clear and correct grammar, though we don't use it in modern speech. We've not chosen 'otherwise', else we waste five columns to no end.