"We eten een duur ontbijt."
Translation:We are eating an expensive breakfast.
"Wij" is the stressed form of "we". It just puts a bit more emphasis on the pronoun
I typed it with wij instread of we and it didn't accept it as correct. Is the difference between these two is that the wij is more formal while we more informal ?
It is accepted only not when it's a listening exercise due to the difference in pronunciation. (Already explained before)
Does it mean that in all listening exercises we should be using WE over WIJ? Only because of the engine?
No, you need to write what is said. So we when the voice says we, and wij when the voice says wij.
The pronunciation of ontbijt in the audio is very odd. It sounds more like /ɔnt'bɛːt/ than the expected /'ɔntbɛit/.