I hate it when you do that.

[Kellogg]

In "I hate it when you do that," some people classify "when you do that" as an adverbial clause, while others classify "when you do that" as a noun clause that explains the formal object "it."

May I have your comments? Thank you.

[Alan]

Personally I favour the noun clause interprepation since it makes 'it' rather more meaningful, but that is simply a preference. The construction is fundamentally ambiguous!