ask sb. to do sth. 是正确用法。 1、并没有ask sb. doing sth.这个说法, 请求别人做的事情是未发生的,不能用进行时。 2、让某人做某事句型还有: make sb. do sth. ；let sb. do sth.；have sb. do sth；get sb. to do sth. 等。 3、接双宾语句型：Subject(主语+Verb(谓语+ Indirect object(间接宾语+Direct object (直接宾语例: My father bought me a present. 例句: 1、I've come to ask you to do me a favour. 我来这儿是想请你帮个忙。 2、Don't ask me to do impossible things. 别叫我做办不到的事。
3、It is not in reason to ask him to do such a job. 让他去从事这种工作是不合常情的。4、Is this what they ask you to do? 这些是他们要你去做的吗？ 5、I couldn't ask you to do that. that's too much. 我不能要你怎么做，那太麻烦你了。
