Is there any difference in the pronunciations of 'er' and 'ihr'? In the tutorials, it gets confusing when the speaker says those words and I tend to get my answers wrong in that case.
There should be a difference. "er" sounds something like AIR and "ihr" sounds something like EAR. However, I agree that the recorded voice is often hard to understand. Try clicking on the SLOW speed key and listen to each word - it sometimes helps.