～ばかりに— Simply Because (Regret)

• パスポートを忘れたばかりに、旅行に行けなかった。

  Pasupooto o wasureta bakari ni, ryokou ni ikenakatta.

  Just because I forgot my passport, I couldn't go on the trip.

  忘れた + ばかりに links one small mistake to a regrettable result

• 彼は正直に話したばかりに、罰を受けた。

  Kare wa shoujiki ni hanashita bakari ni, batsu o uketa.

  Simply because he spoke honestly, he was punished.

  ばかりに stresses that the single cause led to an unfair bad outcome

• お金がないばかりに、大学をあきらめた。

  Okane ga nai bakari ni, daigaku o akirameta.

  Just because I had no money, I gave up on university.

  ばかりに expresses regret that this one condition caused the outcome

• ・The result clause is almost always negative/regrettable.
• ・Carries a tone of 'if only that one thing had been different.'
• ・Do not confuse with ばかり (only) — the に and negative result are the key markers.

Commonly confused with

The JLPT rarely asks whether you recognise a pattern — it asks which of several similar patterns fits. These are the ones ～ばかりに is tested against.

• ～あまり(に) — So Much That It Overwhelms
• ～おかげで — Thanks To
• ～せいで — Because Of (And I Blame It)
• ～せいか — Perhaps Because Of
• ～からといって — Just Because
• ～ことから — Judging From The Fact
• 次第だ／次第で — It All Depends
• だけあって — Living Up to It