Using capital letters
You should always use a capital letter in the following situations:
In the names of people, places, or related words
Use a capital letter when you are writing the names of people, places, and words relating to them:
At the beginning of a sentence
Use a capital letter at the beginning of a sentence:
The museum has huge potential. It will be a great boost to the area and we are really excited about it.
In the titles of books, films, organizations, etc.
Use a capital letter in the titles of books and other publications, films, organizations, special days, etc. In such cases, you need a capital letter for all the main words but not for the connecting words such as a, an, the, or, and, etc.:
Pride and Prejudice
the Houses of Parliament.
If you’re using the first letter of the abbreviated words, every letter should be a capital, e.g.:
BBC (British Broadcasting Corporation)
USA (United States of America)
MP (Member of Parliament)
See more about writing abbreviations.
People often don’t use capital letters when they’re writing emails or other informal messages, but it’s important to use them in formal writing.