English is a funny language in that there are so many words that sound the same but have different meanings, or one is actually derived from another. In the case of these two examples, they can be used interchangeably, BUT especially and specially have somewhat of a different meaning, at least in American English. If I were to say "I made these cookies specially for you!" it has a different connotation than "I made these cookies especially for you!" There is more of an exclusive meaning behind especially. Especially can emphasize something more so than specially can. If I were to say that I made cookies a certain or different way, I would use specially. If I made the cookies only for you and you alone, I would use especially. Especially excludes. With until or till, they are both the same. I can be outside until it is dark, or I can be outside till it is dark. Till is more slang-sounding than until, so I would not use till in a more professional or proper setting. I hope this helps!

There is an overlap in the use of the two words and they can often be interchanged. There are a couple of occasions where one would work better than the other, but you'd be understood if you used either. Especially is more common than specially I'd say.

great.i want know this difference too..