In English, there are many rules for using capital letters. As an academic writer, I understood its importance after publishing my research papers in international peer-reviewed journals. Following are the rules that explain where to capitalize a letter. This could be a handy reference for you. So bookmark this page in your browser for future reference.
Rule 1: The first word in a sentence
Eg: Welcome to my website
Rule 2: The pronoun
Eg: She and I are good friends.
Rule 3: Abbreviations and acronyms formed from the first letters of words
Eg: UNESCO, IBM, USA, SAARC
Rule 4: All proper nouns. Proper nouns include
a. Names of deities   –   Allah, God, Jesus, Shiva
b. Names of people and their titles  –   Mr. and Mrs. Smith
President Abdul Kalam
But NOT a title without a name  –   That economist is the former prime minister
c. Names of specific groups of people (nationalities, races, and ethnic groups), languages, and religions – Asian, American, African, Muslim, Hindu, Sentinelese.
d. Names of specific places on a map  –   New Delhi, Aurangzeb Road, South Pole, Indian Ocean
e. Name of specific geographic areas   –   the Middle East, Eastern Europe
But NOT the names of compass directions  –  Drive north for two blocks, and then turn west
f. Names of days, months, and special days  –   Friday, July, Ramadan
But NOT the names of the seasons   –   spring, summer, winter, autumn
g. Names of specific structures such as buildings, bridges, dams, monuments – Taj Mahal, Annai Indira Gandhi Road Bridge
h. Names of specific organizations (government agencies, businesses, schools, clubs, etc..,)Â Â –Â Â Revenue Department, Indian Bank, Arsenal Football Club.
i. Name of school/college subjects with course numbers  –  Cost Accounting 415, Managerial Economics 521
j. First, last, and all important words in the titles of books, magazines, newspapers, plays, films, stories, songs, paintings, statues, television programs  –  Origin of Species, The Wealth of Nation
   Note: Italicize (or underline) titles of books, magazines, newspapers, plays, and films