However, "pleuvoir" is an irregular verb, and the past participle is rarely used on its own. Instead, it's typically used in conjunction with the auxiliary verb "avoir" to form compound tenses:
* Il a plu. (It has rained.)
* Il avait plu. (It had rained.)
* Il aura plu. (It will have rained.)
Therefore, while "plu" is the past participle, it's not often used independently.