Use a capital letter at the start of a sentence. (This includes sentences within quotation marks.)|
The words following a colon do not usually start with a capital letter, unless the introduction is short and the words after the colon are the main idea and a complete sentence.
A Capital Letter to Start a SentenceStart every new sentence with a capital letter. This seems like a fairly simply ruling, but there are some quirks.
Capital Letters after Colons, Dashes, or SemicolonsWhen a sentence is divided by a dash, a semicolon, or a colon, you will often have two "sentences" either side of it. In fact, these are not two sentences but two independent clauses. Only the first one (i.e., the one that starts the sentence) gets a capital letter. For example:
Of course, if the first word should have a capital letter in its own right (e.g., it's a proper noun (e.g., London, George Harrison, Wal-Mart) or an abbreviation (e.g., CNN, BBC, Nato)), then obviously it keeps its capital letter.
Capital Letters within Quotation MarksIf your sentence contains a quotation which is a standalone sentence, start the quotation with a capital letter. For example:
BEWARE THE RUN-ON ERROR
Once you have expressed a complete idea, you must put a full stop and end the sentence. Do not insert a comma and continue writing. This is a very common mistake. For example:
Read more about run-on errors.
YOU CAN EXTEND A SENTENCE...JUST NOT WITH A COMMA
Occasionally, it may be appropriate to use a colon, a dash, or a semicolon to extend a sentence. For example:
START A NEW SENTENCE WITH HOWEVER
The word however (usually written However,) nearly always starts a new sentence. It is a common mistake to merge sentences using a comma and however. For example:
Read more about using a semicolon before however.
OF COURSE, HOWEVER DOES NOT ALWAYS START A SENTENCE
Be aware that the word however does not always start a new sentence. For example: