～ば～ものを (～ba～mono o)
Explanation
Expresses regret or a missed opportunity: 'if only', 'had I but...'.
Formation
Verb-ば + Verb-past + ものを, い-Adjective + ければ + ものを, な-Adjective/Noun + であれば + ものを, etc.
Detailed Explanation
The ～ば～ものを grammar point shows regret about what could have been, often translated as 'if only...' or 'it would have been better if...'. It can be used with verbs, adjectives, or nouns, usually in a past or conditional form.
Examples
早く起きれば、遅刻しなかったものを。
Hayaku okireba, chikoku shinakatta mono o.
If only I'd woken up early, I wouldn't have been late.
もっと頑張れば、テストに合格したものを。
Motto ganbareba, tesuto ni goukaku shita mono o.
If only I'd tried harder, I would have passed the test.
お金があれば、新しい車を買ったものを。
Okane ga areba, atarashii kuruma o katta mono o.
If only I had the money, I would have bought a new car.
友達がいれば、一緒に遊んだものを。
Tomodachi ga ireba, issho ni asonda mono o.
If only I had a friend, I would have hung out together.
Grammar content sourced from hanabira.org.