especially as above all,ex: i do not like bright color,especially black; i like the country side, especially in spring; this is a very common word, especially in spokenenglish.
specially is showed for a particular purpose,ex:those shoes were specially made for me; i came here specially see you
but when show as something very important or unusual,u can use specially also can use especially,ex:it is not specially cold today / it is not especially cold today.
in front of the preposition phrase or conjunction, use especially,ex.:especially on sunday,especially in the north,especially when we have visitors