分詞作狀語，它的邏輯主語通常應是句子主語，否則會出錯。請看下例。如：

　　(1) Finding her car stolen, ______.

　　A. a policeman was asked to help B. the area was searched thoroughly

　　C. it was looked for everywhere D. she hurried to a policeman for help

　　此題答案應選D，因為句首用作狀語的現在分詞短語finding her car stolen 的邏輯主語應是她，而不是 a policeman, the area, it 等。

　　在使用分詞的邏輯主語時還要注意根據句意判斷是主動還是被動，如：

　　(2) _____ many times, he still didnt understand it.

　　A. Having been told B. Though to be told

　　C. Having told D. He was told

　　根據句意，he 與 tell 應是被動關系。從時間上看，應該是被告訴在先，沒有理解在后，故選A。比較下題由于句中用了并列連詞but，情況有所不同。如：

　　(3) _____ many times, but he still didnt understand it.

　　A. Having been told B. Though he was told

　　C. To have been told D. He was told

　　此題答案選D，句中的并列連詞 but 表明整個句子為并列句，同時表明 but 前應是一個獨立的句子，而不能是一個非謂語動詞短語(所以不能選A或C)。