Translation:This big boy is his brother.
Not sure that 'duży chłopiec' should be translated by "big boy"...
"Big boy" cracked me up XD haha
why is brother in the instrumental form
The irregular verb być requires its object to be instrumental as rule.
so "ten" can mean "this" & "that"?
Yes. Polish uses "ten/ten/tamten" and English uses "this/that/that".
Who's a big boy? You are!
thought CHLOPIEC small boy ?
It might still work if there's a boy standing next to him who is even shorter.
I see from another perspective now thank you.
I firstly thought of the sentence as reference to the boys age.
Expand my thoughts