I honestly don't know how exactly the program works. I'm just told to sing. Nothing else.
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*puts nerd glasses on*
It's because of the way you pronounce the letter combinations in the word 'Touch' and 'Separate'. In the word 'Separate' the letter combination of the 'Sep' causes your lips to touch when pronouncing the 'p'. In the word 'Touch' none of the letter combinations causes your lips to touch when pronouncing the word.
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I've HEARD of it. I don't know what its about though.
