Question

1. If anyone doesn't find me, I will die.

2. If no one finds me, I will die.

(Are both grammatical?)

3. You have to practice playing the piano.

4. You have to practice to play the piano.

5. You have to practice the piano.

(Which ones are correct from #3 to #5?)

Answer 1

#2 is correct. You can change #1 to read - If someone doesn't find me, I will die.

3-5 are all correct.