1) I simply refuse to go

我就是不去!
2) I just do not get it.

我就是不能理解。
3) Yes, I'm coming right now.

是, 我就来。
4) This is Xiao Fu speaking.

我就是。
5) This is he/she./Speaking./It's…

我就是……
6) Oh, yes, I am.

哦,我就是。
参考词条