We see THESE families that are desperate for housing. Council houses (see: 12:19-12:24)
We see THE families that are desperate for housing.
I, as a non-native speaker of English, would think that we are talking about a specific group of people, which would require "the" rather than "these". And the sentences seem to be the same to me, however as a non-native speaker I can't be %100 sure.
So, I would like to ask is there a difference between the sentences above? If there is no difference, can we use "these or this in place of "the" as a definite article without causing any change in the meaning of the sentence? For instance:
1- Did you see the man wearing a blue shirt?
2- Did you see this man wearing a blue shirt?