I am having some trouble telling the difference between the two. Don't they both mean "myself"? And so does 私自身, right? I don't get the difference, when you would you use any of them and how to choose. I guess that 自分 doesn't necessarily point to "me" and therefore could mean "yourself" or "himself" depending on context, but then does the same apply to 自身? Someone help me ~~ ;w;
自分 means oneself, and it can refer to the speaker or somebody else.
自身 also means oneself, and it can refer to the speaker or somebody else.
The difference is that 自身 is a suffix that attaches to a pronoun (or name) to emphasize it (it works just like the word 自体). In the sentence below, 自身 is attached to ジェーン to emphasize that ジェーン is the one who wrote the letter (I got this sentence from jisho.org):
On the other hand, 自分 doesn't attach to other words as a suffix, it just means "oneself" and you have to figure out who it's referring to based on context. In the sentence below, notice that 自分 doesn't attach directly to その役員; instead, it is used later in the sentence to refer to その役員 (This sentence is also from jisho):
Conflicting reports prompted the director to reconsider her position.
Then you have the special case where the thing 自身 attaches to is 自分, making 自分自身.
We use them like this
In those case, both are totally same meaning. In my opinion, when 'を''の'and so on, are attached after ’自分自身’or ’自分’, you can use them as same meanings.
in that case, you can't replace 自分自身 with 自分, and this sentence often seen and heard. I can't recall other good examples now.
Except those examples, in most case, you can't replace 自分 with 自分自身. You could say ’自分自身’ is a special expression of '自分'.