Many an ESOL teacher will, I'm sure, groan with me when I mention the pronunciation of the -ed past simple or past participle ending. Students here insist on pronouncing the e, so that the -ed is pronounced as a separate syllable, for no one has ever told them that it is only thus pronounced after a t or a d [as in wanted or decided]. Of all past simple or participle forms, the word finished seems to cause the most pronunciation difficulties, with student after student pronouncing it as three separate syllables: fin-ish-ed.
I have therefore made it my mission in life to teach my modicani students the correct pronunciation of this word and I have taken to yelling, "Music to my ears!" or playing the chimes of Big Ben when they get it right. Nevertheless, my mission seems doomed to failure and, to paraphrase Queen Mary Tudor,
"When I am dead and opened" [I mean op-en-ed] "you shall find finish[e]d lying in my heart."