What is the correct interrogative form of 'He has been here before'?

The correct interrogative form of the statement "He has been here before" is "Has he been here before?" This transformation maintains the original meaning of the statement while converting it into a question.

In this interrogative form, the auxiliary verb "has" is placed at the beginning of the sentence, which is a standard structure for forming present perfect questions in English. The rest of the sentence follows with the subject "he" and the past participle "been" alongside the place "here," completing the thought as a question about his previous visits.

Other options might misrepresent the tense or the nuance of the inquiry. For instance, the first choice, while it is a plausible question, introduces "ever," which shifts the focus towards lifetime experiences rather than specifically about previous occasions at this location. The third choice employs the present tense "is" instead of the present perfect "has," resulting in a question that does not align with the original statement's context regarding prior experiences. The last choice uses "had," which indicates a past perfect tense, suggesting a different timeframe that does not relate directly to the statement about his experiences up to the present.