When we want to describe something that is working properly, we often use the phrase "be functional." However, there are many synonyms that can be used to convey the same message. The most common synonyms include "operate efficiently," "perform effectively," "work correctly," and "run smoothly." Other possible synonyms could be "serve its purpose," "do the job," "fulfill its function," "be in working order," or "be operational." These phrases all convey the idea that something is functioning as it should, whether it be a machine, a system, or a person. By using these synonyms, we can communicate more precisely and effectively in a variety of contexts.