After almost 3 months of practice, I can finally pronounce the "rr" in Spanish. However, it is still very hard to put it in the word, let along in the sentence. For me, the vibration of tongue is not really controlled by my mind. It is almost like learning snap your finger, you just keep snapping it until you hear something.
I have no idea why I could not do it before, or why I can do it now neither. More interestingly, after the first several times of success, you just lose the ability of doing it wrong.
