Can anyone tell the the difference between these two words, and in which condition should they be used?
I couldn't find anything better than this:
The meanings and usage of these two similar-sounding words overlap quite a bit, so it can be hard to figure out which one to use when. But here are some simple rules:
1) Use especially to mean “very” or “extremely,” as in these examples:
There is nothing especially radical about that idea.
The food was not especially good.
2) Use especially when something stands out from all the others, and you want the meaning of “particularly,” as in these examples:
She can't be sure she will win, especially at this early stage of the campaign.
The appetizers and especially the soup were delicious.
3) When you want to convey the meaning “for a special purpose,” or “specifically,” you can use either especially or specially. They are both correct.
The speech was written especially/specially for the occasion.
4) When you want to convey the meaning “in a special manner”, as in this example below, use specially. In this context, especially would sound odd or wrong to most native speakers.
I don't want to be treated specially.
I don't want to be treated especially.