An ELT Glossary : Bound morphemes

  • Definition : A morpheme (the smallest part of a word which carries meaning) which cannot exist in isolation but must be attached to a free morpheme or series of morphemes including at least one free morpheme (stem). 
  • Example :  un- in unhappy indicating negative meaning, or the -ed past tense marker.
  • Bound morphemes are nearly always affixes -  in English,   prefixes (occurring in front of the free morpheme, as un- in the example above) or suffixes (occurring after it, as the past - ed suffix). Some languages also have other types of affix - eg infixes - bound morphemes which occur in the middle of the stem.
  • Alternatively they may be what are known as cranberry morphemes - ie like the cran- in cranberry, or the luke- in lukewarm, unrecognisable in the current standard language as having independent meaning. They usually have an etymological explanation. For example luke- comes from the Middle English adjective leuk meaning tepid. (For example, in the 14th century cookbook Utilis Coquinaris, a recipe for blancmange included the instruction : wash clene the rys in leuk water. The word leuk no longer exists as a free morpheme, but has lingered in the compound.