Hi @pavankumarnr,
Thanks for posting your question here!
For distinguishing major and minor, I would have two tips:
- Use chords or keys to practice telling major from minor in a different context. For example, you might find it easier to tell major and minor triads apart than the intervals of major and minor thirds, so practising those may be more rewarding while also building up your sense of relative pitch and letting you improve on the interval recognition in an indirect way.
- Mix up your intervals. If you’re trying to tell major from minor thirds, or major from minor sevenths, etc. this can be difficult, because the intervals are close to the same pitch distance. So you can distinguish them based on their sound character but not based on their size. Mix up the intervals you’re practising with to include more differently-sized intervals (e.g. practising major third vs minor seventh, and minor third vs major seventh) for a while, and you’ll train your ears in a different way which should help when you return to major third vs minor third etc.
I would not recommend being a perfectionist. It’s important to spend some time on small groups of intervals before moving on, so that you can solidify those and avoid confusing your ears (and yourself!) too quickly. More details here.
Beyond that, my advice would be similar to what I suggested for @mrear recently – there are other resources you should consider that are more closely related to your overall goal of playing guitar by ear.
Does that help?