For my multi-talented sister, able do anything with ease, it seems that my commonplace self is something whose existence she finds very hard to forgive.
妹は英仏語を使いこなす。
My sister has a good command of both English and French.
彼女は日本で育ったにもかかわらず、英語を自由に使いこなす。
彼は英語をうまく使いこなす。
He has a good command of English.
彼はフランス語を自由に使いこなすことにかけてはだれにも劣らない。
He is second to none in his command of French.
彼の英語を使いこなす力は私のそれと等しい。
His command of English is on a par with mine.
彼にはその仕事をこなす能力がある。
He has the ability to do the work.
彼にはその仕事をきちんとこなす能力がない。
He doesn't have the ability to do the work properly.
彼には、その仕事をきちんとこなす能力はない。
He doesn't have the ability to do the work properly.