Is there a difference between "each of which/some of which" and "each of them/some of them"?
Is there a difference between the expressions "each of which" and "each of them", and also for "some of which" and "some of them"?
For example:
The paragraph is composed of sentences, for each of them (or for each of which) the style is analysed.
The paragraph is composed of sentences, some of them (or some of which) are nominal sentences, the others are verbal sentences.
Solution 1:
The two constructions are interchangeable in meaning and use, except for one small detail: The phrase "each/some of which" requires a verb, while "each/some of them" doesn't:
1.1. The paragraph is composed of sentences, each of them nominal.
1.2. The paragraph is composed of sentences, some (of them) nominal, others (of them) verbal.2.1. The paragraph is composed of sentences, each of which is nominal.
2.2. The paragraph is composed of sentences, some of which are nominal, others (of which are) verbal.
(The phrases in parentheses are optional. Of course, if you keep the second in the sentence with two, you have to keep the first as well.)
2.1. and 2.2. use adjective clauses (the "which" clauses that follow the first comma). 1.1. and 1.2. make use of a different sort of technical construction than in 2.1. and 2.2. I think they are a combination of prepositional and participial phrases with words omitted as understood, but I'm not sure:
1.1. The paragraph is composed of sentences, (with) each of them (being) nominal.
Whatever they are called, they are very standard, and they work equally well.
Solution 2:
'Each of which' refer to each of the member in the data set but 'some of which' does not refer to the whole set.