兩個拼寫的都是正確的。譯為adj.熟練的。 skillful為英式的，skilful為美式的。

【例句】1. Soon they became very skillful in answering such questions. 很快他們就會很熟練地回答這種問題了.2. The promoter matched the young boxer with a more skillful fighter. 拳擊競賽主辦者讓這位年輕拳擊手和技術更嫻熟的拳師較量.3. It was very skillful of you to repair my bicycle. 你修好了我的腳踏車,技術真好.4. That is a skillful operation. 那是一次技術高超的手術.5. A smooth sea never made a skillful mariner. 平靜的大海決不能造就熟練的水手.6. One"s art of fraud is skillful [ superb ]. 騙術 高明.7. Military tactics are skillful. 兵法巧妙.8. 41 A smooth sea never made a skillful mariner. 41平靜的大海練不出好水手.9. Japanese managers are very skillful in easing out undesirable employees. 日本的經理們在辭退不合需要的職員方面是非常精明的.10. Speed requires training, confidence, morale, suitable transport, andskillful leadership. 要想達到迅速的目的,則有賴於訓練 、 信心 、 士氣 、 以及良好的運輸, 精明的領導等等.

雖然這兩個詞很多時候可以換用，但是不是同一個詞。 這兩個詞讀音相同，詞性相同 ，是同義詞。 兩個詞都能表達“having or showing knowledge and skill and aptitude” 但是skillful還有“done with delicacy and skill”的意思，而skilful沒有