Sen erkek(man)-sin(second person singular) : You are a man.
Sen erkek(man)-se(conditional)-n(second person singular)... :If you are a man...
As you can see person suffixes look different although they are different versions of same one. But you can consider them different to make things easy. To know when to use what you should check the conjugations tables for tenses and moods. But here is a list of what you will see:
1st person sin: -m, -ım, -im, -um, -üm
2nd person sin: -n, -(s)ın, -(s)in, -(s)un, -(s)ün
3rd person sin: -
1st person plu: -ız, -iz, -uz, -üz, -k
2nd person plu: -(s)ınız, -(s)iniz, -(s)unuz, -(s)ünüz
3rd person plu: -lar, -ler
I am not exactly sure what exactly you are trying to say :) I will try to answer, but if you could as your question again in a different way, I would like that
Erkek can mean "man" in the sense of being "male." It has more to do with the concept of "man" as a gender.
Adam can mean "man" in the sense of being a "guy/physical being." It has more to do with "man" as a physical being.