My student is such a weak student but I am trying to make her understand. I try to simplify things. She still can not write on a piece of paper whethet two notes form a semitone or a tone. What is a simple way of explainng to her how to from tones and semitones without the help of the keyboard on a piece of paper? I explain to her that E to F and B to C naturals form semitones. All the other natural cobinations are tones. If we sharpen or flatten both notes of the semitones we get again semitones, if we sharpen or flatten both notes of the other combinations we get again tones. Now how do I explain in a simple way the other cobinations for example the combinations with one note flattened or one note sharp?