disability，inability

這一對詞都表示“無能”之意，但涵義有細微的差異。

Disability著重表示“因受傷而變殘廢所引起的無能”(lacking ability caused by injury)或“因天生的缺陷而導致的無能”(inherent defect);用于法律方面，它表示“不夠資格”、“不合格”(legal disqualification)之意。例：

He has a disability pension because he lost his legs while he was in the army.

他領取傷殘撫恤金，因為他在軍隊服役時失去了雙腿。

He was always cheerful in spite of his disability.

他雖然有殘疾(殘廢)，但心情一直很愉快。

Inability 著重表示“缺少能力”或“缺乏手段”(lack of power or means)的意味。如：

His inability to undertake the work is due to his physical disabilities.

他沒有能力承擔該工作，是由于他的殘疾。

Can you account for your inability to pay the debt?

您能否解釋無法償債的原因嗎?