【Godwithgigico】評論
*have trouble Ving = have difficulty in Ving =in 為介係詞 所以 Ving =動名詞來源 : https://en.oxforddictionaries.com/definition/difficulty
【Tea Tai】評論
S. + have + trouble (麻煩)、problems (問題)、difficulty、a hard time (困難)+ (in) + Ving其實是省略了介係詞 in,表示「要做某事有困難,不易做到某事」