Which sentence would to grammatically correct?
1) Remember never to do that ever again.
2) Remember to never do that ever again.
3) Remember to never to do that ever again.
1. is correct.
The other two sentences have split infinitives.
#1 is closest, but to have "never" and "ever" in the same sentence is redundant. I'd remove "ever."
The grammatically correct sentence would be: "Remember never to do that ever again." (Option 1)
To determine the correct sentence, you need to understand the correct placement of adverbs, specifically "never" in this case. In English grammar, adverbs like "never" usually come before the main verb in a sentence.
In this case, the main verb is "do," and "never" should come before it, which is correctly portrayed in option 1. Option 2 places "never" after the verb, resulting in a grammatically incorrect sentence. Option 3 includes an unnecessary repetition of "to," making it incorrect as well.