Prothesis and epenthesis are the introduction of additional
Prothesis and epenthesis are the introduction of additional
sounds, initially and medially respectively. The addition of the /e/
that made Latin words like scola 'school' into Portuguese escola is the only example of prothesis in foure historical linguistics
textbooks I consulted. As for epenthesis, an example other than the one
Crystal cites was the /d/ inserted into ME thunrian to give
us the Modern English thunder.