<human>: Can you succinctly summarize the text in 1-3 sentences?

Odd situation spanning 2 countries:

My grandmother had 3 kids: My father, uncle#1, uncle #2

Uncle #1 moved to another country, and grandmother bought him an apartment.

Fast forward in time (and due to our less than awesome genetics), my grandmother died, then my father died (10+ yrs ago), then uncle #2 died (5 yrs ago, without kids) when I was a teen.

Fast forward some more, and uncle #1 contacted me to let me know he needs me to sign papers saying I'm giving him my portion of the apartment.

Turns out the apartment was never in his name. It was in my dead grandmother's name. 

And, at some point uncle #1 actually sold the apartment (I'm not sure when/if my GM or father were still alive) but was never able to give the paperwork to the new owner since it wasn't in his name.

So, for the last 3-4 years he's been trying to get the apartment under his name so he can give the new owner the documentation.

Problem: GM, my father, and uncle #2 didn't have wills when they died

So it seems,  as next of kin I was part owner of an apartment in a different county that was technically sold to someone else many years ago.

Now: I'm being asked to sign documents (in a language I can't read) forfeiting my portion of the apartment. I'm obviously not signing anything in a language I can't read. 

Question: Would I still need to pay US/foreign taxes on my portion of the apartment if I sign papers relinquishing my portion?
<bot>: apparently unknowingly inherited a portion of a foreign apartment 10+ years ago when my father died, now being asked to sign papers giving up my portion.