The adjective especial is not just a misheard form of special. It’s a real word, meaning of special importance. While special is synonymous with specific or particular, especial is synonymous with uncommon or exceptional. Think of especial in relation to its corresponding adverb, especially. Especially is more common, but especial can apply to qualities that something has especially—for example, an especially sleepy kitten has an especial sleepiness.
Special has taken over much of especial‘s territory, and the latter may someday be pushed out of the language.
Examples
Especial is still relatively strong in British English—for example:
In England, Alexander at first seemed out of his depth when keeping to the spinners, having especial trouble in “reading” Sonny Ramadhin. [Telegraph]
But little dogs are viewed with especial suspicion and derision by Iranian hardliners … [Daily Mail]
… [Y]ou can be sure he took especial interest in the first direct meeting for six years of Mike Blair and Chris Cusiter. [Scotsman]
Most American writers would use special in place of especial in these instances.
