Is there an adjective in English which describes *a device that works properly*? As opposed to '***broken***: damaged not or working properly'. Is it correct to use the adjective '***healthy***'? As in > Is the vacuum cleaner *healthy*? It sounds rather strange to me in this sentence. But I've seen it used with car or engine. I was wondering if it's correct to use it with any noun of the sort, and whether it's commonly used.