1. Noun Phrases:
* Singular, non-human referent: "I saw a cat. It was black." (refers to "a cat")
* Singular, abstract noun: "The weather is awful. It's pouring rain." (refers to "the weather")
* Singular, indefinite noun: "There's someone at the door. It must be the mailman." (refers to "someone")
* Collective noun: "The team is playing well. It's on a winning streak." (refers to "the team")
* Clause functioning as noun: "It's a shame that he didn't win." (refers to the clause "that he didn't win")
2. Clauses:
* That-clause: "It's obvious that he's guilty."
* Wh-clause: "It's unclear who stole the money."
* Infinitive clause: "It's fun to go to the beach."
* Gerund phrase: "It's dangerous driving in this weather."
3. Other Pronoun Categories:
* Impersonal "it": "It's cold outside." (refers to a state of being)
* Dummy "it": "It's time to go." (no specific referent)
* Emphatic "it": "It was John who broke the vase." (used for emphasis)
Examples:
* Noun: "The house is old. It needs to be renovated."
* Clause: "It's a mystery why he left."
* Impersonal: "It's getting dark."
* Dummy: "It's getting late."
* Emphatic: "It was Sarah who won the lottery."
Note:
The specific grammatical category that "it" anticipates depends on the context of the sentence. You can usually determine the intended referent by looking at the surrounding words and the overall meaning of the sentence.