Commas

Commas [ , ] mark off bits of sentences to clarify meaning.

Use a comma to:

• Separate parts of a sentence (or link equal elements of a sentence) 
  The student was interested, so she listened to the lecture intently.
  
• Join two sentences with a conjunction 
  Students must attend lectures, and they understand more content if they have completed the set reading.
  
• Separate words from the rest of the sentence 
  Jane, however, refuses to study.
  
• Introduce
  Despite the availability of podcasts, students who miss lectures often do not catch up on the work.
  
• Complete 
  The student did well in the assignment, to his relief.
  
• Separate items on a list or list items in a series.