Irregular Spanish Past Participles
I have just corrected an exercise for some students who had to fill the gaps with the correct present perfect translation. They made a great attempt but nearly all of their past participles were incorrect because they used logic to guess as the past participle for verbs such as hacer (hacido) abrir (abrido) etc.
Unfortunately for them many of the examples required an irregular past participle,
for anyone who would like a list of irregular Spanish Past Participles as well as a list of some adjectives that differ from the usual past participle form here is an article that I've just put together. I hope it's useful.