英语语法：动名词和不定式作表语,语意的混淆 不定式表一次具体的动作 动名词表周期性重复的动作

英语语法：动名词和不定式作表语,语意的混淆 不定式表一次具体的动作 动名词表周期性重复的动作
例1：the idea is to sell things
这里卖东西明显不是只卖1次 为什么人家老外就用不定式?

答：不定式表一次具体的动作 动名词表周期性重复的动作,这是对的.
The idea is to sell things.这句话是有上文的.the idea 可换作his idea,可能是某人的一个想法、主意.
这与My job is teaching English.不是一会事.
例1：the idea is to sell things
这里卖东西明显不是只卖1次 为什么人家老外就用不定式?
答：你说这个例句是老外说的,请问老外是在什么情况下说的吗?不会突然冒出这么一句话来吧.请提供上下文.
确切地说,动名词和不定式的区别是：前者表示“抽象的、经常性的动作”,后直表示“具体的、将来的一个动作”.
再问： 1.这句话没上文 2.不是my job 而是the job 可换作his job 可能是某人的一次工作、一次任务
再答： 不可能没上下文！ 我找到了： KINGDOMGarage sale in Jeddah By Michael Bou-Nacklie Saudi GazetteJEDDAH – This Ramadan many young Saudis will be exposed to something they may not be used to - a garage sale. The idea is fairly common in the US but here it is strange to most people. The idea is to sell things you don’t need/want anymore so others can enjoy them instead of them ending up at the local dump. A social networking website, Fainak.com will host a garage sale from Sept. 10-17 on Tahliah Street in the La Promenade 2 parking lot starting from 9 P.M. The proceeds will be used to help the needy and the poor. “We want to have an event involving young people and locals which has never been done before. At first we were afraid of how it would turn out, but in just days we registered 100 participants. We were only expecting 50 but so many people want to participate,” said Maha Mahdaly, event coordinator and team manager of Fainak.com. She said they wanted to put on an event which was both fun and would be helpful to the community. “Every participant will have the option to donate 100 percent, 50 percent or 10 percent of the money they make, to the needy.” Most of the items on sale will range from Ipods to Playstations to books and DVDs. 一个人一生中会有很多的ideas, 这个idea就是要做某件事情，所以用The idea is to do sth. 是的，His job is doing sth. 和His job is to do sth. 都是成立的。如： His job is teaching English. 他的工作是教英语。 这个job是职业。 His job today is to sweep the floor. 他今天的任务是扫地。这个job=work,task