The end of a complete sentence should be marked by a period, a question mark, or an exclamation point. If a sentence is not complete and it is terminated by a period, we have a sentence fragment as in the sentence below.
Incorrect: You can use any resources. To complete your take-home exam.
Correct: You can use any resources to complete your take-home exam.
The end of a complete sentence should be marked by a period, a question mark, or an exclamation point.
Sentence fragments are discussed in a different section of this tutorial. This section will explore the uses of punctuation marks used to mark the end of sentences.
A period is used to signal the end of a complete sentence.
Correct: This is the best paper I've ever written.
A period is also used at the end of an indirect question.
Correct: The teacher asked us if we understood the assignment.
Polite requests can be followed either by a period or by a question mark.
Correct: Will you please mail this letter for me.
Correct: Will you please mail this letter for me?
A period should be placed after every part of the abbreviation:
Very common abbreviations and units of measure don't take periods:
Academic degrees can be written with or without periods:
Lower case abbreviations are usually written with periods:
i.e. Government agencies and international organizations are written without periods:
Direct questions are followed by a question mark.
Correct: The teacher asked, "Do you understand the assignment?"
Exclamatory sentences should be followed by an exclamation point.
Correct: Wow! That's incredible!