YOU SAID:

I can't understand why you can't just decant the vial.

INTO JAPANESE

なぜバイアルをデカントできないのか理解できません。

BACK INTO ENGLISH

I don't understand why I can't decant the vial.

INTO JAPANESE

なぜバイアルをデカントできないのかわかりません。

BACK INTO ENGLISH

I don't understand why I can't decant the vial.