Okay, the user wants me to translate "sub-grade" into Swedish. Let me think about the correct term here. "Sub-grade" can refer to a lower grade or a subsidiary grade. In Swedish, "sub" is often translated as "under" or "underordnad." For "grade," the common translation is "klass" or "nivå." So "sub-grade" might be "underklass" or "underordnad klass." But I should check if there's a standard term used in specific contexts like education or classification. If it's in an academic setting, "underklass" might be more appropriate. Alternatively, "nivå" could work if it's about levels. I need to make sure there's no direct equivalent that's more commonly used. Let me confirm by thinking of examples. If someone says "sub-grade students," it would be "underklassstudenter" or "studenter på underordnad nivå." But maybe "underklass" is the direct translation. Since the user didn't specify the context, I'll go with "underklass" as the most straightforward translation. Also, checking if the original term is already in Swedish, but "sub-grade" isn't, so translation is needed. Alright, I'll provide "underklass" as the translation.