Words are made of different letters respectively sounds. We usually perceive them as separate but it's a smooth transition from one letter to another. Have you ever tried slowing your speech so far down and pay attention to the sound between two letters? Where does the a end, where does the O begin? Paying close attention to speech might take the stuttering away - works for me although I had psychedelics to help me with. Stuttering has so many different reasons. From trauma, injury, neurological etc. Just saying " can't be cured" is a bit too easy. As is " there's a cure" It simply depends