你把这两句话中的“得了”当成相同的词语了，其实它不完全不同。 ”谁等得（读de轻声）了（读liao3)那么久？““了”在这里是表示可能或不可能的意思。因此，这句话是说“谁也不能等那么久。） ”饭得（读de2)了吗?""得”在这里是完成的意思。饭得了吗？是饭做好（完成）了吗？ 所以是完全不同的两个词语。

”谁等得了那么久？“here means "Who can wait for such a long time?" or "Who is able to wait so long?" I this situation, a verb with "得了" following, means "able to do (that behavior)." For example, "谁受得了你啊？（Who is able to bear you?）" "你吃得了这么多吗(Are you able to eat that much ?)" Actually, "得" itself can have such meaning too. For example, "你买这么多书，看得过来吗(Are you able to read that much)？” “这么多单词，记得住吗(are you able to remember that much)？” The antonym of 得 here is 不. For example, “我等不了这么久or “我吃不了这么多” or“我记不住这么多单词”. ”饭得了吗?" here means "Is the meal done?" 得了here means: 了 le. Notice that such expression is quiet colloquial, even a little "北京话". you can see "得了"="了"（le ） "饭做得了吗？=饭做了吗/做饭了吗" " 你吃得了吗？=你吃了吗” Other examples that use "得了“: 小明的作文得了一等奖（get; win; achieve）. 老王得了肺癌（catch a disease） 得了吧，别装傻了(Come on!) 不得了了！(Oh, my God.); 小小年纪就学会偷东西，长大还得了？（Both means something is serious） 关于读音 了读le 只有一种用法，为，助词，用在动词后，表达动作的结束和完成。 如好了，完了，吃了，得了（There 得 just means done in a colloquial situation）。 了读liao3 四种用法 1. 明白，明了v. & adj.(comprehended, understand， perceptive)： 一目了然，了然于胸，了解。 2. 完毕 v.（done, complete. 这个比较难和助词区分。当“了”显然做动词而不是助词的时候，读liao3）：不了了之，责任未了，了却心愿。 3.完全 adv （absolutely 副词，修饰形容词，一般固定搭配“了无”）：了无新意，了无生趣。 4. 与“得”和“不”连用，表完成（固定搭配，词性接近动词）：不得了，他等得了这么久，我等不了这么久。

”谁等得了那么久？“ deng3 de2 liao3 ，verb+ complement. 等得了，等不了。 ”饭得了吗?" de2 le 方言，意思是“好了吗？” 希望能解决你的问题。

得 1. to obtain / to get / to gain / to catch (a disease) / proper / suitable / proud / contented / to allow / to permit / ready / finished 2. structural particle: used after a verb (or adjective as main verb), linking it to following phrase indicating effect, degree, possibility etc 3. to have to / must / ought to / to need to It all depends on the context. For example,If by itself, it most probably means "got it" , indicating a: forbidden “得，别说了”b: agreement “得"，就这么办”. In your examples, it has the meaning of #2 得能莫忘 (from the Thousand Characters Classic) Literally, "obtaining ability not forget". i.e. when you become able (or had achieved something), do not forget those who had helped. 近水樓台先得月, 向陽花木易為春 suitable - 得体, 得法 satisfaction - 得意, 揚揚自得 ought to - 不得随地吐痰

The first one "谁等得了那么久？" means "没人等得了那么久。" means "It had been too long time to wait . " others , like " 谁吃得了那么多？"The food is more than a person could eat . “谁受得了那么吵？” The speaker could not stand the noise anymore. "得了"means "be able to do" . The second one "饭得了吗？" is the same as “饭做得了吗？”是在文言文和现代文之间的,回答“饭做得了。一会儿就端出来。”，means "Is the dinner ready(prepared)?"。others , like “钱得了吗？”"Have you got the money already?"“肉票得了吗？”"Have you got the hostage already?""得了"means "the work has been done, ... is ready",this one is not use very often.