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.
プロジェクトは順調に進んでいます。
The project is going smoothly.
表面は滑らかです。
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.
仕事は順調に進んでいます。
Work is progressing smoothly.
The meeting ended smoothly.
A loanword from English, very common in spoken Japanese. Emphasizes lack of friction or difficulty.
手続きがスムーズにいった。
The procedure went smoothly.
Formal term often used in business or official contexts to describe smooth operation or communication.
両国の関係は円滑に進んでいる。
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.
車が滑らかに走っている。
The car is running smoothly.
この机の表面は滑らかだ。
The surface of this desk is smooth.
Also used for physical smoothness, especially in casual contexts. Overlaps with the process meaning.
スムーズに動くドア。
A door that moves smoothly.
Describing a person who handles a situation with ease and without awkwardness.
Means doing something flawlessly and without any mistakes, often implying social grace.
彼はそつなく挨拶を済ませた。
He smoothly finished his greetings.
Literally 'without stagnation', used for speech that flows smoothly without hesitation.
彼女は淀みなく話し続けた。
She continued speaking smoothly.
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.