In Japanese, "don't" is often expressed using the negative imperative form of a verb, created by adding な (na) to the plain form, such as 行くな (iku na) for "Don't go." In more polite contexts, ないでください (naide kudasai) is used, as in 行かないでください (ikanai de kudasai), meaning "Please don't go." For casual situations, simply saying ないで (naide), like 行かないで (ikanai de), can convey the same meaning. Another common phrase is やめて (yamete) or やめてください (yamete kudasai), used to mean "Don't do that" or "Please stop." Japanese often softens commands to maintain politeness, so the appropriate phrasing depends on the relationship and situation.