"able" 是一个 形容词，而不是情态动词。它用来描述某人或某事物具有某种能力或可能性。例如：
She is able to speak French.
They are able to solve complex problems.
情态动词则是一类特殊的助动词，用来表示说话人的能力、许可、请求、建议、义务或必要性等，常见的情态动词包括 can, could, may, might, must, have to, should, would 等。例如：
She can speak English very well.
You must be careful when crossing the street.
希望这些信息对你有所帮助。
