Use a period to mark the end of a declarative sentence, an indirect question, or an abbreviation.

Note: Some abbreviations do not include periods (see M6); always check your dictionary to be sure. In addition, many specialized professional and academic fields have their own systems for handling abbreviations.

P13 Question Marks

Add a question mark after a direct question.

Avoid using question marks to express irony or sarcasm. Use them sparingly to question the accuracy of a preceding word or figure.

P14 Exclamation Points

Use an exclamation point to show strong emotion or emphasis.

Use exclamation points sparingly. Replace inappropriate or excessive exclamation points with periods.