This is the difference between teen and ty.

这就是 teen 和 ty 之间的区别。

You've got to tell me whether I'm saying teen or ty.

你得告诉我我是说的是 teen 还是 ty。

OK, I heard umpteen and umpty, which end in the morphemes -teen and –ty, like fifteen and fifty.

好的，我听到了无数，还有若干这两个词，它们像十五和四十一样，是以teen和ty音素结尾的。

Whereas if I'm saying " thirty, thirty" , you will notice " thir" is loud and long, and the last part " ty" or " dy" is quiet.

而如果我说“三十， 三十”，你会注意到“thir” 又大又长，而最后一部分“ty” 或“dy” 是安静的。