Use Present Perfect Simple or Present Perfect Progressive.
1.I have (to diet) for the past few years. I have (to try) all sorts of diets. 2. I have (to take) dancing lessons since last year. I have (to learn) three dances. 3. I have (to study) English since I was 7. Now I can speak fluently. 4. – Oh, you look great! – Yes, I have (to ride) my bike for a month. 5. I have (to do) sports for two years. I have (to have) good results.
1) I have been dieting for the past few years. I have tried all sorts of diets.
2) I have been taking dancing lessons since last year. I have learned three dances.
3) I have been studying English since I was 7. Now I can speak fluently.
4) -Oh, you look great!-Yes, I have been riding my bike for a month.
5) I have been doing sports for two years. I have had good results.