On the CHAT site of LatinStackExchange there has been a debate on Latin impersonal verbs of the kind "pudet me" = "it shames me"/"I am ashamed". This included the role of "it". Then, the English "it", in "it rains". I thought that this is a subject; a pronoun standing in for "the sky"/"the cloud" i.e. "the cloud (it) rains".
Alternatively, "it" has been described as a "dummy subject" because "rains" is an intransitive verb, requiring no direct object — an explanation that is not entirely clear.
What is the role of "it" in "it rains"?