How do proper nouns differ from common nouns?

Proper nouns are usually not used with articles. For example: I live in Delhi, He works at Google. However, exceptions apply in cases when the article is a part of the name.

For instance:

The University of Delhi has many colleges affiliated to it.

 The Times of India is a prominent English-language newspaper in India.

Proper nouns are usually not used with articles. For example: I live in Delhi, He works at Google. However, exceptions apply in cases when the article is a part of the name.

For instance:

The University of Delhi has many colleges affiliated to it.

 The Times of India is a prominent English-language newspaper in India.

Proper adjectives are adjectives derived from a proper noun and describes a noun by relating it to a specific person, place or thing.

Example:

I love American culture. (derived from America)

She enjoys Indian cuisine. (derived from India)

Proper adjectives are adjectives derived from a proper noun and describes a noun by relating it to a specific person, place or thing.

Example:

I love American culture. (derived from America)

She enjoys Indian cuisine. (derived from India)

Yes, certain proper nouns are plural like the Himalayas, the Ahujas. In these cases, no apostrophe is used.

Example:

The Smiths moved in our block yesterday. (Family or Dynasty names)

The Lord of the Rings books are a good read. (Series Titles)

This song is sung by the Beatles. (Musical/Performance group)