1. It's no use worrying about it.
2. It's no use to worry about it.
3. There is no use worrying about it.
4. There is no use to worry about it.
Which ones are grammatical? In #1 and #2, does 'it' on the left refer to 'worrying about it'?
All are fine. #s 1 and 3 are most commonly used, but all are correct.
That "It" in 1 and 2 is that impersonal "it" that doesn't refer to anything. It's just a way to introduce a sentence, just as "There" is in 3 and 4.
It is no use being worried.Is it correct?
Out of the four options provided, options 1 and 3 are grammatically correct. Both "It's no use worrying about it" and "There is no use worrying about it" are acceptable constructions. The pronoun "it" in options 1 and 3 does refer to "worrying about it." However, options 2 and 4 are not grammatically correct. The phrase "It's no use to worry about it" and "There is no use to worry about it" have unnecessary prepositions ("to") that make them incorrect.
Out of the four statements you presented:
1. "It's no use worrying about it." - This sentence is grammatically correct. In this statement, "it" refers to the action of "worrying about it."
2. "It's no use to worry about it." - This sentence is grammatically incorrect. While the phrase "it's no use" is idiomatic and correct, the addition of "to" before "worry" is not necessary. Therefore, it should be: "It's no use worrying about it."
3. "There is no use worrying about it." - This sentence is grammatically correct. The subject "there" is used as a placeholder, and "it" again refers to "worrying about it."
4. "There is no use to worry about it." - This sentence is grammatically incorrect. Similar to the second statement, the addition of "to" before "worry" is unnecessary. It should be: "There is no use worrying about it."
In summary, statements #1 and #3 are grammatically correct, and in both cases, "it" refers to "worrying about it."