part
‘part of’
Part of or a part of something is one of the pieces or elements that it consists of. You use part of or a part of in front of the singular form of a countable noun, or in front of an uncountable noun.
I've told her part of the story, but not all of it.
Using the internet is a part of everyday life for most people.
‘some of’ and ‘many of’
Don't use ‘part of’ or ‘a part of’ in front of a plural noun phrase. Don't say, for example, ‘Part of the students have no books’. Say ‘Some of the students have no books’.
Some of the players looked very tired.
Some of us have finished.
Don't say ‘A large part of the houses have flat roofs’. Say ‘Many of the houses have flat roofs’.
Many of the old people remember the war.
➜ See some
➜ See many