不能确定

• be uncertain of

例句

1. 我不能确定埃拉是不是爱我。但是她要走了，也许是一去不回头了。我决定豁出去向她求婚。
   I wasn't sure whether Ella loved me or not, but she was leaving—perhaps for good. I decided to fling caution to the winds and ask her to marry me.
2. 我不能确定上一次看见她是什麽时候。
   I'm not sure when I saw her last.