看受詞能否主動執行補語的動作，例如：

I keep my arms waving until the train leave the station. (我使我的手臂保持揮動直到火車離站為止。)[手可以主動揮動，故使用現在分詞waving]

It is very dangerous for many pet keepers leave their pets untied on the street. (很多飼主將他們的寵物沒有綁好鍊繩就放到街上是很危險的。)[寵物無法主動沒綁好鍊繩，故使用過去分詞untied]

那the news that my grandmother fell sick made me  ---    是要填worrying 還是worried