1. It hardly rained last summer.
2. Hardly did it rain last summer.
(Is #2 OK?)
3. Even if the sun were to rise in the west, I would not change my mind.
4.Were the sun to rise in the west, I would not change my mind.
(Is #4 OK?)
No, 2 is not OK!! The placement of the adverb matters.
4 is not incorrect, but it's not a pattern that's used much.
1. Yes, sentence #1 is grammatically correct. It conveys the meaning that very little rain occurred during last summer.
To determine the correctness of #2, we need to evaluate the structure of the sentence. In English, to create a statement that emphasizes a negative or unusual event, we can use inversion. This means that the subject and auxiliary verb are inverted. In this case, "did" (the auxiliary verb) is placed before the subject "it." While sentence #2 is grammatically correct, it sounds slightly formal or literary. It is less commonly used in everyday conversation.
3. Yes, sentence #3 is grammatically correct. It expresses a hypothetical situation where the sun rises in the west, but the speaker claims that it wouldn't change their opinion or decision.
Regarding #4, it is incorrect. The verb "were" should be following "if," and the verb "to rise" should be in its base form without the "-ing" ending. Thus, the correct sentence would be: "If the sun were to rise in the west, I would not change my mind."
In summary, sentences #1 and #3 are correct. Sentence #2 may be less commonly used in everyday conversation, and sentence #4 requires the correction mentioned above.