Systrarna sjunger--- In English, we differentiate between "the sisters sing" (meaning that singing is a talent or a hobby of the sisters) and "the sisters are singing" (meaning they are singing right now). In Swedish, does "systrarna sjunger" have only one meaning--- that the sisters are singing right now?
Fun fact of the day: English sister is actually already influenced by Scandinavian languages. In Old English, the word was sweoster, and if it hadn't been for the Scandinavian influence, the English word today would have been something like swester (so closer to German Schwester).
It's kind of like a throaty, guttural h, but not really. Try making an /h/ sound but pushing the air towards the back roof of your mouth. Also try to blow a decent amount of air out of your mouth when making the sound. Took me a bit to get it right when I moved to Sweden :) Northern Sweden and Finland use 'sh' whereas middle and southern Sweden use the ɧ. http://en.wikipedia.org/wiki/Swedish_phonology This might help a bit^ You can practice with the number 7 (sju) and pretty much just keep trying to say it and listening to different recordings of people saying it until you can mimic it!
Move your top teeth so they touch your bottom lip like you were saying an F, then put your tongue back as though you were going to say G. Then round your lips like you were saying an O and exhale. Should sound Swedish enough to fool someone until they listen more closely :)