"presumably" is from the word 'presume' (to assume, to guess, to pre-judge)
"apparently" is from 'apparent' (to appear, to seem, i.e. what it looks like).
Presumably you have studied English really well. This is my guess (my presumption), because your English is apparently flawless. I presume you have studied English well - because I do not know your story. But it appears/ it is apparent that you know it so well that your grammar and vocabulary are perfect.
So, xxxx this is what it appears like/is apparent, ...so I presume (I assume/guess) that you have studied/worked hard to get to this level.