a part or part of...

is it possible to say" Moscow is A part of Russia."? I know that we must say" it is part of… " without A. Only a big part, a good part etc. I need explanation quite urgently. Can you help?

Hi ClassCentre,

Welcome to english-test.net! Both your phrases are possible depending on what exactly you want to say. For example: Moscow is a part of Russia that plays a very important role.
“part of” is general while “a part of” is more specific.

Hope this helps.

TOEIC listening, question-response: How much interest does First Bank pay?[YSaerTTEW443543]

Thanks a lot, Torsten!