のに

When のに appears at the end of a sentence (sentence-final particle), it expresses regret or wistful disappointment about a counterfactual situation—something that did not happen but the speaker wishes had. Commonly paired with conditional forms (〜ば、〜たら) or past progressive (〜ていた) in the preceding clause. The speaker implies "if only things had been different." Distinct from the connective のに (contrast/despite), which links two clauses mid-sentence.