"I know both of your children."
Translation:Conosco entrambi i tuoi figli.
Conoscere is to know people, places and things. Sapere is to know facts and skills. Here's a good link that explains the difference: https://robinonawire.wordpress.com/2012/01/11/difference-between-sapere-conoscere-both-mean-to-know-present-tense/
Not in English. "Your both" is backward.
You are not confusing "you are" with "your", are you?
- You are = you're, because "you're" is a contraction.
- You are does not equal Your, because "your" is a possessive.
In the first example, you are calling two (both) people children (contraction/ you're/ you are), in the second one, both of the children belong to you (possessive/ your).
I'm not 100% sure, but that sounds off to my ear, corresponding to "I know your children, both". I think that in Italian, as in English, you normally put "tutti e due" (both) before "i tuoi figli" (your children). Also as in English, you can break it up into two sentences, one of them incomplete: Conosco i tuoi figli. Tutti e due. (I know your children. Both of them.)