I know 新しい{あたらしい} and 新た{あらた} and I understood that the latter is usually used in newspaper because it brings more politeness/formality.
However, I encountered 新規{しんき} in a newspaper article:
新型コロナウイルスの感染が広がるロシアで、1日の新規感染者数や死者数が連日、記録更新を続けている。
According to Jisho dictionary, 新規{しんき} means new/fresh as well. It makes me wonder, what are the nuances between this word and 新しい{あたらしい} and 新た{あらた} ? Is it mostly a prefix word like 新 kanji (e.g. 新年, 新学期...) ?
新規 and 新たな cannot be used as a predicate, and they cannot be used in comparative sentences, either.
| pre-noun adjectival | adverbial | comparison | predicate |
|---|---|---|---|
| 新しい計画 | 新しく計画する | これより新しい計画 | この計画は新しい |
| 新たな計画 | 新たに計画する | ❌これより新たな計画 | ❌この計画は新ただ |
| 新規(の)計画 | 新規に計画する | ❌これより新規な計画 | ❌この計画は新規だ |
新しい is a plain word, 新た is a bookish and a little dramatic word (∼ "brand-new"), and 新規 is a technical-sounding word. 新規 is not a word we commonly see in lyrics. 新たな夢 sounds more dramatic than 新しい夢, but 新規の夢 sounds simply odd.
As 新規 is a kango (Sino-Japanese word with on-readings), it's often used before another kango.
I may be wrong, but 新規 may tend to mean "first-time" rather than "new". 新規客 and 新しい客 can both refer to "first-time customer (who has never visited the store before)" and "new customer (e.g., 8th visitor of the day after the first 7)", but I feel 新規客 tends to refer to the former. There is even an expression ご新規さん. The same can be said for 新規感染 vs 新たな感染; both can refer to first-time infection and reinfection, but 新規感染 tends to refer to the former.
