You can say "bi-racial" to refer to someone who is of 2 different races. But you can never go wrong with "mixed race" and it can refer to more than 2 races as well. English & Afghan aren't races though, they're nationalites / ethnicities. It would be more accurate to use "mixed heritage" situation where the 2 parents are the same race but have different nationalities or ethnicities.

Dear Edgar, I believe the more formal term is "bi-racial" but that of "mixed parentage" is also appropriate. Best, Lida

Biologically speaking, there are no different races in the human beings. Therefore no one can be in this condition. ;-)

We can use the word 'mixed race' to describe such a child, regardless of what those two races are. You always have to be careful when using vocabulary relating to race and ethnicity, but the term 'mixed race' is not generally seen as offensive.