functions, operates, runs, performs, is effective, is successful, is functional, is operational, is in working order, is usable
funktionsfähig - funktionstüchtig - betriebsbereit - einsatzbereit - funktionsfähig im Einsatz - voll funktionsfähig - intakt - gebrauchsfertig - nutzbar - einsatzfähig
“Is functional” is an English phrase typically used as the predicate in a sentence to indicate that something works correctly or serves its intended purpose. It combines the verb “is” (third‑person singular of “to be”) with the adjective “functional”. In everyday usage, it often answers whether a device, system, design, or process operates as expected, even if it may not be aesthetically pleasing or fully optimized. The phrase can appear in technical, informal, or professional contexts, for example: “The prototype is functional, but needs refinement.” It emphasizes usability and operability rather than appearance or extra features.