they are german还是germans?

they are german还是germans? They are German 和 They are Germans 两种说法那个正确?还是都不正确? 他们不是德国人 用英语怎么说?They are not Germans.还是German.要变复数吗? 2 Germans boys 还是2 German boy 是a german 还是 a germans German变复数是Germans还是Germen? 是a German 还是 a Germans? They are German teachers. 英语：德国人 ：German的复数形式是Germen还是Germans还是Germens? They speak German.So I think they are ____(German). The three men are ( ).A.German B.Germany C.Germen D.Germans German的复数为啥是Germans