What is the difference between a phrase and a clause?

Solution 1:

The short answer: clauses contain a subject and its verb, while phrases do not. Note that phrases may contain nouns and verbals, but won't have the noun as the verb's actor.

The long answer: see this page from the University of Chicago which has several examples.

Solution 2:

From: http://www.oxforddictionaries.com/words/sentences-clauses-and-phrases

• sentence:

  • group of words that makes complete sense
  • contains a main verb
  • begins with a capital letter
  • usually ends in a punctuation like period . or exclamation mark !
  • can contain multiple clauses, separated by conjunctions like and, punctuation like commas , or stuff like if ... then, who, that

  He is the author     who          has been writing a very good book.
     [clause 1]     [separator]              [clause 2]
  

• clause:

  • group of words that contains a verb
  • contains phrases

• phrase:

  • small group of words that forms a meaningful unit within a clause or another phrase.
  • many types, including:
    • noun phrase: a very good book
    • adjective phrase: very good
    • verb phrase: has been writing