是a American还是an American

是a American还是an American American前面用a还是an American前加a还是an? I'm American,I'm an American和 I'm an American girl这三种表达方式都可以吗?如果可以的话,I'm an American里American 是名词,那I'm American里的American是名词还是形容词? American的冠词He is American boy中间要加a还是an啊? She is an A_____ girl.是填America 还是American American用a还是an为什么不要说American是元音音标开头（不是元音音标,它的开头是/?/） ----American boy (a/an/the) she is an American.还是she is American 是American Chinese还是 Chinese American? 应该是are you american还是在american前加an?是不是除了chinese和japanese之外,其他的都要加a? 是a还是an 一般现在时与现在完成时‘The computer ___(give) me a voice but it's an American voice,'Stephen often says,with a smile.是填gives还是has given. kate is ( ）.I’m（ ）American.填a或an还是什麽都不填 “American” 和 “university”这两个名词前加 a 还是 an ,说明理由.急求答案 is alice an american 是知道呀 “他是一个美国人”可不可以说成“He is an American.如题.是一定得说成He is American.还是两种都可以? The man was a famous American sports star语法对吗?（是famous在前还是American在前）