What is the past participle of “ride”?

The past participle form of “ride” is ridden. It’s used to form perfect tenses (e.g., “I have ridden on an elephant before”) and to form the passive voice (e.g., “The bike hasn’t been ridden in a long time”).

It’s wrong to use the past simple form “rode” instead in these contexts. For example, “The bike hasn’t been rode” is incorrect.