starts a sentence that holds true despite the one before: "even so", "but still". The first sentence is an obstacle, and the second is what happens or what you do anyway.
。。
I failed many times. But still, I didn't give up.
。。
It's raining. Even so, I'm going out.
。。
It was tough. But still, it was fun.
それでも or でも
is a plain "but" and can set any two facts side by side. それでも needs the first sentence to be a reason for the second not to happen.
。、。
My older brother is tall. But my younger brother is short.
。。
The pay is low. Even so, I like this job.
- × 兄は背が高い。それでも弟は低い → 兄は背が高い。でも、弟は低い
それでも or それなのに
Both say the result goes against expectations. complains about a result you did not want. それでも has no complaint in it, so it can lead into what you intend to do.
。。
I was told it's dangerous. Even so, I intend to go.
。。
I studied hard. And still I failed.
- × 危険だと言われた。それなのに行くつもりだ → 危険だと言われた。それでも行くつもりだ
In a question
At the start of a question, それでも asks whether someone still means to go ahead after what has been said.
きごう？
And you're still going to keep at it?
Lingaku