what is the difference between similarly and likewise
I am not an English teacher, but I guess I can give you an acceptable answer for this question.
"Similarly" and "likewise" are both adverbs, so it is not surprising for you to find them confusing. However, if you look the two words up in a dictionary, you get to see the difference:
looking or being almost, but not exactly, the same
Cars must stop at red traffic lights: similarly (= in a similar way), bicycles should stop too.
(You do not stop a car and a bicycle in exactly the same way.)
in the same way
Just water these plants twice a week, and likewise the ones in the bedroom.
(Water these plants and those in the bedroom twice a week.)
So, the difference between the two is quite subtle.
Hope this helps.
Cambridge Dictionaries Online - Cambridge University Press