Why on Earth do some people think that this is meant to be a phrasebook?
It could be that he is the one who cooked the potato and we don't eat just anybody's potatoes, but we eat his potato every time he cooks it for us. It just seems like one wouldn't be enough though, so maybe it is prepared in such a way that we each eat some of the potato along with other food. I want that recipe!
If a plausible scenario helps to hold the attention for grasping the grammar:
He developed a potato hybrid which we eat. • He grows and vends produce of which the potato we are eating is one. • We are eating ample portion servings intended for sharing, we are sharing our garden salad and pasta with him in kind as he shares his potato with us.
Her salads and dressings are scrumptious! He is so finicky, and is not at all a salad person, but even he eats her salads.
Is the "a" necessary here? I thought it was only applicable for possessive pronouns like meu etc.
delas=their (just for feminine group(s) )
deles=their (their can refers to male group(s) or (a) group(s) with male and female)