Nothing wrong with your English, 'mappsi30'!
It's a long time since I had any dealings with the 3 Series cars, but your problem is almost certainly associated with the drive belt(s). One or both could possibly be broken, or more likely - from the 'scratching sound' - out of adjustment. Contamination with oil is also a possibility, but that and going out of adjustment are more usually gradual failures, whereas breakage will result in a sudden one.
Alternatively, the selector rod may have become disconnected or there may be a fault with the selector mechanism.
I've just had a quick look in my Haynes workshop manual for you and this pretty much confirms the above. Let's hope it is just a simple fix!
Regards, John.