A more natural sounding English sentence would be 'you can also listen...' Can I translate tillegg as also?
As 'også' is 'also' in Norwegian you probably cannot translate 'i tillegg' as 'also' for Duo exercises, but in practice you may be able to. Just keep in mind that tillegg means addition. You may remember 'legge til' meaning 'to add' with numbers.
This English translation sounds quite awkward
This sounds really strange in English. If someone said this to me I would wonder if they actually had a good grasp of the language.
English would move the "additionally" to the front, and also would accept "in addition".
Would "even" be a good translation for tillegg? Is it the Norwegian form of "till och med"?
Norwegian for "till och med" is "til og med" and that would be a good translation for "even".
"i tillegg" is more like "additionally" though.
Oh, I see, thanks.
Does this have to be definitive? listen to THE radio rather than listen to A radio?
You wouldn't normally say 'listen to a radio' in English. Likewise, you wouldn't say 'watch a tv'.