English grammar - Roger Berry 2012

A2.5 Common and proper nouns
A2 Nouns
Section A. Introduction

We can make two important distinctions between types of noun. The first is between common and proper nouns. Common nouns make up the great majority of nouns in a language; they are the words we are mostly dealing with in this section and the rest of the book, for example all the nouns in Activities A2.2 and A2.3 above. Proper nouns are the ’names’ of unique people, places, geographical features, organisations, and so on; they have no lexical meaning (and generally do not appear in dictionaries). In writ­ing we can recognise proper nouns because they start with a capital letter, for example:

London, Leicester Square, Kilimanjaro, Microsoft, Congress, Fred Smith, India

One formal feature is that they tend to appear with no determiner or modification, though actually the commonly precedes certain types of proper noun: rivers (the Thames), mountain ranges (the Alps) and so on (and is also capitalised in a few cases: The Hague, The Times). It is more accurate to say that proper nouns do not allow any contrast in determiners. However, there are situations where they are found with determiners or modification (or in the plural):

There are two Mark Browns in my class.

They say he’s the next Maradona.

He remembered an England of green fields and endless summers.

We say that these nouns have been converted into common nouns (even though the capital letter is retained).