Expletive infixation is a process by which an expletive or
profanity is inserted into a word, usually for intensification.
It is similar to tmesis, but not all instances are covered by
the usual definition of tmesis because the words are not
necessarily compounds. Although most speakers are not exposed to
these formations until after childhood, they can form new
examples readily once introduced to the process, and their
judgments of which formations are acceptable are remarkably
consistent. This suggests that the rules for the placement of
the expletive are not arbitrary, but instead derive from
fundamental aspects of English phonology. A simple rule is that
the insertion occurs at a syllable boundary, usually just before
the primary stressed syllable. Thus, one hears abso-
fuckin'-lutely rather than *ab-fuckin'-solutely. This rule is
insufficient to describe examples such as un-fuckin'-believable,
however, so modifications to this rule are proposed such as
morpheme boundaries taking precedence over stress. Co