Translation guide
The English adverb "sporadically" describes actions or events that occur at irregular intervals, not continuously or predictably. In Japanese, this concept is expressed through various adverbs and phrases that emphasize irregularity, infrequency, or scattered occurrence.
To describe something that happens occasionally with no set pattern, often with gaps of time in between.
The most common and neutral way to say 'sometimes' or 'occasionally'. It implies irregular intervals but is less emphatic about the lack of pattern than 'sporadically'.
彼は時々遅刻する。
He is late sporadically.
Literally 'in a scattered manner', this is a direct equivalent for 'sporadically'. It emphasizes isolated, scattered occurrences. Slightly formal, common in news and reports.
散発的に雨が降った。
It rained sporadically.
Means 'intermittently', with starts and stops. Suitable when an action resumes after pauses, but not necessarily at regular intervals.
断続的に銃声が聞こえた。
Gunshots were heard sporadically.
Casual, meaning 'once in a while' or 'occasionally'. Less formal than 時々, often used in spoken Japanese.
たまに映画を見に行く。
I go to the movies sporadically.
To describe things that appear here and there, not concentrated in one place.
Used for physical objects or locations that are dotted around an area. Often in the form 点在している.
湖の周りに家が点在している。
Houses are scattered sporadically around the lake.
Means 'sparsely' or 'thinly', often for distribution. Can describe attendance, vegetation, etc.
観客はまばらに座っていた。
The audience was seated sporadically.
To emphasize that events are separate and infrequent, often with a nuance of unpredictability.
Literally 'single-shot', meaning one-off or isolated occurrences. Used for events that happen once in a while without repetition.
単発的に問題が発生している。
Problems are occurring sporadically.
A slightly literary or formal word for 'occasionally', similar to 時々 but with a more elegant tone.
時折、彼から連絡がある。
I hear from him sporadically.
散発的に emphasizes isolated, scattered occurrences with no pattern, while 断続的に focuses on the on-and-off nature of an action that stops and starts. Use 散発的に for random events and 断続的に for something that resumes after pauses.
散発的に抗議活動が行われた。
Protests were held sporadically.
断続的に雨が降り続いた。
It rained intermittently (on and off).
While 不規則に (irregularly) can sometimes work, it often implies a lack of rule or pattern in a systematic sense, not just sporadic occurrence. For natural Japanese, prefer the options above.