Dialogue in section 118

Textbooks Latin For Beginners by D'Ooge
1

In section 118, there is a dialogue between Cornelius and Marcus. For the last dialogue by Cornelius:

Mala est fortuna eorum et saepe miseri servi multis cum lacrimis patriam suam desiderant.

the answer key gives the translation as

Bad is their fate and the wretched slaves often long for their fatherland with many tears.

Is writing it as “Mala est fortuna SUARUM et saepe miseri servi multis cum lacrimis patriam suam desiderant” acceptable? Is there any explanation for either one or both?

2

No, it’s not acceptable. suus, a, um is an adjective that needs to be applied to something. Like in

miseri servi multis cum lacrimis patriam suam desiderant

suam is applied to patriam

Also generally suus means belonging to the subject (but not always).