Translation guide
The English adverb "extensively" describes something done in a thorough, wide-ranging, or detailed manner. In Japanese, there is no single direct equivalent; the best choice depends on whether you mean "covering a wide area/range," "in great detail," or "to a large degree."
Expressing that something is done over a broad scope, involving many places, people, or topics.
The most common and versatile adverb for "widely" or "extensively." Used when an action or state covers a broad area or range.
His works are extensively known.
This issue was extensively discussed.
Emphasizes a wide range or variety, often used for activities, knowledge, or offerings.
She reads extensively (across a wide range of books).
Formal phrase meaning "across many fields" or "in many areas." Suitable for academic or business contexts.
He conducted research extensively across many fields.
Expressing that something is done thoroughly, with careful attention to many aspects.
The standard adverb for "in detail" or "thoroughly." Use when "extensively" means covering a topic with depth.
Please explain that point extensively.
He investigated the incident extensively.
Means "thoroughly" or "exhaustively." Stronger than 詳しく, implying no stone left unturned.
Means "minutely" or "in fine detail." Suitable when "extensively" refers to covering many small points.
He explained the plan extensively (in fine detail).
Expressing that something is done a lot, heavily, or on a large scale.
Adverb meaning "greatly" or "very much." Often used when "extensively" modifies a verb like "use," "rely on," or "benefit."
He made extensive use of that technology.
Casual adverb meaning "considerably" or "quite a lot." Works for informal contexts.
Means "substantially" or "drastically." Used for changes, revisions, or increases.
The law was extensively amended.
There is no single Japanese adverb that covers all uses of "extensively." Translating it as 拡張的に (kakuchōteki ni) or 広範囲に (kōhan'i ni) in every case will sound unnatural. Choose the option that matches the intended nuance.
広く (widely) is for breadth, while 詳しく (in detail) is for depth. If you say 広く説明する, it means explaining to a wide audience; 詳しく説明する means explaining in detail.
She has traveled extensively in Asia.
The report extensively covers the economic impact.
They analyzed the problem extensively.
The book was extensively rewritten.