"They deliver books to their students."
Translation:Dostarczają książki ich uczniom.
It's not an "additional complication", if anything, it's a simplification:
- I'm reading my book. - Czytam swoją książkę.
- You're reading your book. - Czytasz swoją książkę.
- He's reading his book. - (On) czyta swoją książkę.
In casual speech czytam moją książkę is widely accepted, thus you will be understood. Czytasz twoją książkę sounds worse, but still understandable. On czyta jego książkę, however, has a completely different meaning (someone else's book).
If you are deliberately planning on learning a "version of Polish" that just close enough to Polish to be understood, I'll have to say that it's probably safer to speak English in the first place.
Those words don't have the letter J.
"swoich" is wrong here.
This sentence actually uses "ich" in the main answer, as we considered it more probable that "they" are a delivery company and "their" refers to the teachers, therefore the words don't describe the same people. Although "swoim", if we consider "they" and "their" to be about the same people, works.