In the following dialog, both
‘the people who we don’t know’ and
‘Ø people who we don’t know’
might mean either
‘all the people who we don’t know’ or
‘some of the people who we don’t know.’
‘The people who ...’ sounds more like ‘all’ than just ‘Ø people who ...’ according to some native speakers. However, it is IMPLIED/ FELT/ PERCEIVED.
In fact, some native speakers say ‘the people who we don’t know’ sounds no more than just ‘some.’ ‘All or some’ shouldn’t be the determinant.
What do you think is the determinant, then? Any and all insights would be welcome. What do you think is the determinant for deciding you should use ‘the’ or not in the following example? Some people feel you mean ‘all the people’ with ‘the,’ but it’s not the primary determinant, many people think. Would it be your mind that wants to emphasize the meaning of the relative pronouns that places ‘the’ there?
(Suppose there is no context, explicit or implicit, that brings on the definite article in front of ‘people’ and ‘ones’ other than, possibly, the relative noun clauses ‘who we don’t know’ and ‘who we know.’)
Tom: Although the/Ø people who we don’t know from our Sendai factory came to the party, the/Ø ones who we know didn’t.
Sam: Oh, I didn’t even know you have a factory in Sendai.
(I wrote this dialog, thinking ‘we’ are Tom and some of his co-workers, and that it doesn’t include Sam. Sam is from outside Tom’s company)