title_body: What is the difference between an Isolating and an Analytic language?
upvoted_answer: Isolating languages do not use inflectional morphology, i.e., using affixes or other manipulations of roots to create words--all words are seperate, and none contain multiple morphemes.  Vietnamese is an isolating language.
  
  Here's an example: the word snowman.  It has two morphemes: snow- and -man, and therefore has a morpheme-to-word ratio of 2:1.  Or take Spanish corremos, we run, which has three corr-, -e-, and -mos, for the word, present tense, and person/number.  (Please correct me if I am wrong--I don't know Spanish), so its ratio is 3:1.
  In an isolating language, this ratio approaches 1:1--words stand alone and cannot be separated (hence "isolating.")  So, these concepts--"snowman" and "we are running"--would take multiple words to express, as each one would contain only a single morpheme.  Isolating languages have no inflectional morphology and no derivational morphology.
  
  However, analytical languages are a broader category; they have a low morpheme-to-word ratio as well, but--and here's the big but--they can have a derivational morphology.  This means that while "we are running" would still be multiple single-morpheme words like in an isolating language, the word "snowman" could be a two-morpheme word.
  
  Thus, isolating languages are actually a subset of analytic languages.  Analytic languages cover languages with no inflectional morphology and a low morpheme-to-word ratio, while isolating languages have all that and no derivational morphology.