My roommates are always telling me I make up words. While I will admit that in moments of inarticulate stuttering, I have said things such as "mutification," but everyone slips up now and then. I usually let things slide, but recently I said, "I haven't ridden that rollercoaster in years."
My roommates said it's not correct grammar to use ridden, that the correct tense is rode. However, I have always heard it as ride, rode, ridden, just like drive, drove, and driven. They then proceeded to tell me that ridden is an idiom. The next day they told me they had looked it up and not only was ridden an idiom, but a past participle and that a past participle wasn't a real verb and could not be used as one and that the only way to use ridden was as an adjective, such as disease-ridden. I stand by my statement that ridden is a verb and a past participle, which is also a verb, and that it is not an idiom at all.
Please, give us an answer to this situation.
Past Participles? 
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