英语形容词(一般以动词为基础) 的常用终止语和构词元素, 一般增加“能够的; 允许的; 值得的; 需要的; 被______” 的概念, 有时是“充满的, 造成的”, 来自法语 -able, 直接来自拉丁语 -abilis. 它的正确用法是 -ble, 来自拉丁文 -bilis (元音一般来自被加后缀的动词的词干结尾), 它代表PIE *-tro-, 是用来构成工具名词的后缀, 与英语 ruddersaddle (n.) 的第二个音节同源.

在英语中是一个活的元素, 用于由拉丁语或本族语词组成的新式(readable, bearable), 也用于与名词(objectionable, peaceable). 有时具有主动的意义 (suitable, capable), 有时具有中性的意义 (durable, conformable). 它的意义已经变得很有弹性, 如一个 reliable witness, 一个 playable foul ball, perishable goods. 17世纪一位作家有 cadaverable “凡人”.

To take a single example in detail, no-one but a competent philologist can tell whether reasonable comes from the verb or the noun reason, nor whether its original sense was that can be reasoned out, or that can reason, or that can be reasoned with, or that has reason, or that listens to reason, or that is consistent with reason; the ordinary man knows only that it can now mean any of these, & justifiably bases on these & similar facts a generous view of the termination's capabilities; credible meaning for him worthy of credence, why should not reliable & dependable mean worthy of reliance & dependence? [Fowler]

在拉丁语中, -abilis-ibilis 取决于动词的语气元音. 因此, 古法语, 西班牙语, 英语中的变体形式 -ible. 在英语中, -able 往往用于母语(和其他非拉丁语系) 词, -ible 用于明显的拉丁语源词(但也有例外). 拉丁语后缀与 able 在词源上没有联系, 但长期以来, 它一直被人们普遍地联系在一起, 这可能促成了它作为一个活的后缀的活力.