Punctuation is a set of symbols used in writing to help indicate something about the structure of sentences, or to assist readers in knowing when to change the rhythm or the stress of their speaking. Depending on the style of writing and the language used, punctuation may tend towards one of these purposes more than the other. Common units of punctuation in English and many other languages include the comma, period, apostrophe, quotation mark, question mark, exclamation mark, bracket, dash, hyphen, ellipsis, colon, and semicolon. Each of these units indicates a different thing, and some may have multiple meanings depending on context.
The period or full stop, question mark, exclamation mark, and ellipsis all serve to terminate a sentence. A period is the default terminal punctuation mark, used to end a sentence without conveying any additional meaning. A question mark indicates that the preceding sentence takes the form of an interrogative, and may also be read to change the tone when reading aloud to reflect this. An exclamation mark indicates that the preceding sentence is somehow excited or extremely important, and if read aloud should be given special stress. An ellipsis indicates that some part of the sentence is being omitted; this may be used to refer to a theoretical clause, in which case it usually implies a trailing off of the voice when read aloud, or it may indicate that a real part of the sentence is omitted, often used when quoting long passages or quotations.
