Without having reviewed any research specific to this question, it strikes me as a processing error for which psycholinguistics has a strong explanation. When we are inserting phonemes in a word string, we sometimes make retrieval errors. There are substitution errors, anticipation errors, reversal errors, and so on. This particular error may provide some evidence that the phoneme /k/ and /g/ are stored in close proximity--or that similar strings of phonemes like /think/ and /thing/ are stored in close proximity, thus increasing the chance of mis-retrieval. For those who don't remember their phonology, the sounds /k/ and /g/ differ from each other only in the feature "voicing." When retrieving the word /thing/ it is possible that other sounds in the environment condition our chances for retrieving the correct phoneme for the final sound. In the saying provided by Herb, "You have another thing coming" you will note that immediately following "thing" is a word beginning with the related phoneme /k/ (coming). Thus, the version "you have another think coming" can be analyzed as an anticipation error. That is, in rapidly synthesizing this statement, we anticipate the /k/ of "coming" and replace /g/ with /k/. As more than one other person noted, one of the lovable things about this listserv is the way people contribute answers to questions. Thanks so much, John, for the information about listserv. You helped to settle a question that has vexed me for some time. R. Michael Medley, Ph.D. Professor of English Eastern Mennonite University To join or leave this LISTSERV list, please visit the list's web interface at: http://listserv.muohio.edu/archives/ateg.html and select "Join or leave the list" Visit ATEG's web site at http://ateg.org/