How to say "Regret" in Japanese

When translating "regret" into Japanese, you must choose carefully between 後悔 and 惜しむ. In Japanese, 後悔 (こうかい (kōkai)) is typically associated with "regret; repentance" (Syllabus Level: N3) and represents Refers to regretting or repenting past actions or choices. Can be used with する as a verb. On the other hand, 惜しむ (おしむ (oshimu)) maps to "to regret, to惜しむ, to惜しむ" (Syllabus Level: N2) and represents Often used for things one doesn't want to lose, like time, opportunity, or a loved one. Implies reluctance to part with or use something precious.. A literal translation of "regret" can often sound unnatural to native Japanese speakers if mixed up!