A period (.) usually ends a statement or a command written in a neutral tone. In The bus leaves at six. and Please bring your ticket., the period marks the end of each sentence.
Periods at the end of a sentence
Use a period to close a declarative sentence or an imperative that reads as an ordinary instruction. An indirect question can also be part of a statement. I wondered when the bus left. ends with a period, while the direct question When does the bus leave? takes a question mark.
Periods in abbreviations, decimals, and quotations
Some abbreviations use periods, as in Dr. and p.m. If one of those abbreviations ends a statement, its final period also closes the sentence. For example, The bus leaves at 6 p.m. has one period after the m. A period also serves as the decimal point in numbers such as 3.5.
If a quotation comes at the end of a statement, American style puts the final period inside the closing quotation mark. For example, Rae said, “The bus is here.”
