The GVS, as it is known, is exactly what it sounds.

众所周知，GVS 就是它听起来的那样。

Vowels were altered in different ways, or not at all during the GVS.

元音以不同的方式改变，或者在 GVS 期间根本没有改变。

They say noo-n, not known as if the GVS hardly happened while we in the South say stone and known, so couldn't that account for why.

他们说 non，而不是 known，好像元音大转换几乎没有发生一样，而我们在南方说 stone 和 known，这不能解释为什么吗？