1. If I had studied hard, I could have gotten a higher score.
2. If I had studied hard, I could have gotten a better result.
3. If I had studied hard, I could have gotten a good/better grade.
4. If I had studied hard, I could not have gotten a lower score.
5. If I had studied hard, I could not have gotten a bad grade.
6. If I had studied hard, I could have beaten my rival.
7. If I had studied hard, I could have been the top in my class.
(Are they all grammatical?)
4 and 5 don't read well. It's because the main clause is phrased in the negative. How can you rephrase those with "could" and without "not"?
Writeacher you are a genius!!!!!
If I had studied harder <ㅡㅡ> If I had studied hard
What is the difference between them?
Yes, all of the sentences you provided are grammatically correct. They all follow the correct structure for conditional sentences using the third conditional, which is used to talk about unrealized past actions and their hypothetical outcomes. The structure is "if + past perfect (had + past participle), + could/could not + have + past participle."
In all of your sentences, "If I had studied hard" introduces the hypothetical situation, and the rest of the sentence describes the possible outcome based on that condition.
It is worth noting that while the sentences are grammatically correct, the accuracy of the statements depends on the specific context and circumstances.