Proper Noun
Proper nouns are nouns that refer to the name of a specific person, place, or thing.
Proper noun examples
Bijoy Jives in Delhi. It is the capital of India. The river Jamuna flows through Delhi. There are many important buildings in the city. Some of these are the Red Fort, the Qutub Minar, Humayun's Tomb, etc.
In the above passage the words, Delhi, India, Jamuna, Qutub Minar, Humayun. Tomb arc proper nouns because Delhi is the name of a particular city, India is the name of a particular country, Jamuna is the name of a particular river. Qutub Minar and Humayun Tomb are the names of particular historical monuments.
So, They are proper nouns.
Note: (i) The first letter of a proper noun is always capital.
(ii) When the words God and Lord indicate Allah, they are proper nouns and their first letters are always capital but if the words god and lord indicate ruler, master, etc. they do not start with capital letters.
(iii) Proper nouns are sometimes used as common nouns: Examples: (a) Nazrul is the Byron of Bangladesh.
(b) Narayanganj is the Dandee of Bangladesh.