are used for two fundamental purposes: (1)
to indicate the beginning of a sentence; and (2)
to indicate a personal name or the equivalent of one.
First Word of a Sentence
Capitalize the first word of every sentence, of every complete direct quotation, of every line of poetry, and of every paragraph (even though the paragraph consists of a clause), or standing alone in parenthesis.EX.
He asked, "Did you hurt her?" EX.
The manager replied, "We are opening tomorrow morning." EX.
I am running in a marathon on Tuesday.EX.
John reluctantly gave me $50. (He owed me the money.)EX.
"I will train him on Monday," he asserted, "if he shows up on time."NOTE
You do not capitalize the second part of an interrupted quotation unless you use a word that requires a capital letter in any case.