What's the difference between a semicolon and a comma?

The comma is a valuable, useful punctuation device because it separates the structural elements of sentences into manageable segments (Purdue OWL). The word semi means half. According to the Oxford English Dictionary, the word "comma" comes from the Greek komma, which means "something cut off" or "a short clause" (Wikipedia).

Rules

The comma was invented to help readers; Without it, sentence parts can collide into one another unexpectedly, causing misreadings(Hacker 235).

The semicolon is used instead of the comma after items in a series when these items are long or complicated (Word Book).

The Usage

Semicolons

• Use a semicolon between items in a series containing internal punctuation
• between closely related independent clauses not joined with a coordinating

conjunction

• between independent clauses liked with a transitional expression (Hacker 251,252).

commas

• Use a comma between coordinate adjectives not joined by and
• before a coordinating conjunction joining independent clauses
• after an introductory word group
• between all items in a series
• use commas to set off nonrestrictive elements:

"For camp the children needed sturdy shoes, which were expensive."

• use a comma to set off transitional and parenthetical expressions, absolute phrases, and contrasted elements
• use commas to set off nouns of direct address, the words yes and no, interrogative tags, and mild interjections
• use commas with expressions such as he said to set off direct quotations
• use commas with dates, addresses, titles, and numbers
• use commas to pervent confusion (Hacker 235-245).

Links

• OWL Online Writing Lab [(http://owl.english.purdue.edu.)]

Works Cited

• Hacker,Diana. A Writer's Reference. 5th Ed. Boston: Bedford/St. Martin's, 2003
• "Using Commas." OWL.1994-2004 Purdue University Online Writing Lab. 12July.2006 <htt://owl.english.purdue.edu>