你不懂的英文单词

You don't get it.

You don't know English very well.You don't use English very well.You don't speak English very well.know/use/speak/write/read/... 按语境可以互换。

You don't know that或者you know nothing about that不明白的话hi我

You don't feel my pain(sad). 还可以说：You do not feel my torment（suffering）. 希望可以帮到你！~

比较口语的说法，you don't get/catch/follow it。书面一点的，you do not understand。

U not、understand