have done是现在完成时态。现在完成时表示过去发生的动作对现在造成的影响或结果或表示过去的动作或状态持续到现在。例句：We have lived here for two years.我们在这里住了两年了。
现在完成时的构成
肯定句：主语+have/has+done(过去分词)+其它
He has lived in Beijing for 10 years.
一般疑问句：Have/Has+主语+done(过去分词)+其它
Has he lived in Beijing for 10 years?
否定句：主语+have/has+not+done(过去分词)+其它
He has not finished his homework.
