Cambridge Dictionary gives these definitions and examples about "familiar"
easy to recognize because of being seen before
The street was familiar to me.
to know something or someone well
I'm sorry, I'm not familiar with your poetry.
In the following context, which one should I use?
British English is familiar to Chinese kids, since they are taught in school with British English.
Chinese kids are familiar with British English, since they are taught in school with British English.
Could someone please give a hint? Thanks in advance.