I am sitting down是什么时态

I am sitting down是什么时态 I’ am sitting down. 如何翻译? i am down with i am down with sitting down sitting down 一首外国歌曲歌词中有：I let you down . I am the sky ,the star ,the moon ,the sitting sun我要歌名 i am quite busy down here. down 在这里是什么用法? plastiscines的i am down i am down on my I'm sitting down here! Sitting Down Here歌词 will.i.am的《Fall Down》 歌词 I am pretty down中文含义 求plastiscines的I am down 求I AM DOWN TONIGHT的歌词 I am sorry!i feel down,down,down.fogive me,please? I am down as the first presenter.怎么翻译?i am down的用法