Comma

The comma is the most frequently used mark of punctuation within a sentence. It is important to learn to use commas correctly because missing or incorrectly placed commas can change the meaning and lead to misunderstanding.  

Problems with comma use can also affect the author's ethos, that is, the impression of credibility and professionalism that the author conveys to readers through their text.

Some rules for using commas apply to all varieties of academic English, while others vary across varieties and style guides. In the latter case, authors should follow the conventions that apply to their chosen style and use them consistently. 

The sub-sections (left-hand menu) describe different uses of the comma in English with examples.