Translation guide
The English adverb "smoothly" describes an action done without problems, interruptions, or roughness. In Japanese, the best translation depends on whether you mean a process going well, physical movement, or a surface texture.
The project is going smoothly.
The surface is smooth.
Describing that something proceeds easily, without obstacles or delays.
The most common and natural way to say that a plan, project, or event is going smoothly as expected.
Work is progressing smoothly.
The meeting ended smoothly.
A loanword from English, very common in spoken Japanese. Emphasizes lack of friction or difficulty.
The procedure went smoothly.
Formal term often used in business or official contexts to describe smooth operation or communication.
Relations between the two countries are proceeding smoothly.
Describing motion that is fluid, steady, or a surface that is even.
Used for physical smoothness of movement or texture. Can describe a car ride, a dancer's motion, or a surface.
The car is running smoothly.
The surface of this desk is smooth.
Also used for physical smoothness, especially in casual contexts. Overlaps with the process meaning.
A door that moves smoothly.
Describing a person who handles a situation with ease and without awkwardness.
順調に implies that things are going according to plan or schedule, often with a sense of steady progress. スムーズに focuses on the absence of obstacles or friction. In many cases they are interchangeable, but 順調に is slightly more formal and often used in business updates.
滑らかに is for physical smoothness. Using it for a meeting or plan would sound unnatural. Stick to 順調に or スムーズに for abstract smoothness.