not only ... (but also)
このアプリ、操作ばかりじゃなく見た目もいいよね。
kono apuri, sousa bakari ja naku mitame mo ii yo ne.
This app isn't only easy to use — it looks good too. casual
この映画、怖いばかりじゃなく、ちょっと切ないんだよね。
kono eiga, kowai bakari ja naku, chotto setsunai n da yo ne.
This movie isn't only scary — it's a little heartbreaking too. casual
Variants
ばかりではなくbakaridehanakuformal
fuller, more explicit negation with は inserted — the more common shape in written reports and news copy
ばかりじゃなくbakarijanakucolloquial
では→じゃ contraction — the rare spoken realization; real casual conversation reaches for だけじゃなくて instead far more often
ばかりでなく
ばかりでなくbakari de nakuN3neutral