接続・逆接N3
〜だけでなく
not only... but also...
Structure
N + だけでなく；V/い形（普通形）+ だけでなく；な形（語幹）+ な + だけでなく
Explanation
Expresses addition, "not only... but also...". Attaches to nouns or plain verb/adjective forms, often paired with も (値段が安いだけでなく、味もいい).
Examples
この先生は教えるだけでなく、学生の相談にも乗ります。
This teacher not only teaches but also advises students.
彼女は英語だけでなく、中国語も話せます。
She can speak not only English but also Chinese.
Note
だけでなく often pairs with も. In writing, のみならず is more formal.