Thanks for your answer. Will this twisters helps in improving the voice clearity in English.

There are lots of tongue twisters out there you could search for. I would focus on the areas of pronunciation you struggle with. For example, if it's the "b" sound, try this 3 times: Betty Botter bought some butter But she said this butter's bitter If I put it in my batter It will make my batter bitter, But a bit of better butter Will surely make my batter better. So she bought a bit of butter Better than her bitter butter And she put it in her batter And her batter was not bitter. So t'was better Betty Botter Bought a bit of better butter.