"난 내가 생각해도 나쁜놈이다" What is mean? I think I'm a bad guy. right?
I often confuse when i see the sentence that have
난 and 내가 both.

This sentence mean..

I think i am a bad guy.? right?
or

What is mean and grammar of 도 in this sentence.?

or before say this sentence You should heard someone told you are bad guy?
and You are agree?

Question

"난 내가 생각해도 나쁜놈이다"  What is mean? I think I'm a bad guy. right?
I often confuse when i see the sentence that have
난 and 내가  both.

This sentence mean..

I think i am a bad guy.? right?
or

What is mean and grammar of 도 in this sentence.?

or before say this sentence You should heard someone told you are bad guy?
and You are agree?

Answer

난 is a short form of 나는
나는 is composed of
나+는 
는 is a topic marker

내가 is composed of
나+가
가 is a subjective particle.

난 내가 생각해도 나쁜놈이다
Even if I think of it, I am a bad guy.
= Even in my thought, I am a bad guy.
= I also agree that I am a bad guy.

도 is a emphasizing particle which means "even,also"