This causes a problem with “they” in this case; “Chris and Pat went to their car” becomes unambiguously “Chris and Pat went to Pat’s car” if “they” can refer to “Pat”, leaving us with no pronoun for “Chris and Pat”.
It sounds like all these (counterfactual?) people who speak “proper English” need to adapt their language.
It sounds like all these (counterfactual?) people who speak “proper English” need to adapt their language.