It is normal for languages as living organisms to have alternating pronunciations and spellings in certain cases that do not follow a fixed grammar rule

Oh dear. You really would argue the opposite of anything I say, wouldn't you? Even something as blatant as this?

All I did was point out there was nothing strange about the pronunciation, it was simply the difference between the simple past verb form and the past participle.

Or are you suggesting that we shouldn't (as teachers) be aware of the difference between the two?

Do stop harping on with your 'descriptive grammar' strawman now, it's just boring. No decent teacher in their right mind would expect new learners of a language to acquire said new language without grammar rules with which to decode the language. Do keep highlighting your lack of basic knowledge on the subject, the lengths you go to in order to post stalk me all the while nailing the coffin shut on any shred of credibility you had, it's amusing watching you fail time and again!