we are late already.新概念60课课文,为什么不说we have been late already?

already翻译为已经,按我们的语法角度来说句中一般有already ,since等词出现,此词的语态是完成时,have done sth。we are late already说明迟到这种现象是发生频率较高,演变成一种习惯了,其实最初是不迟到的,后来经常性迟到,便默认为一种习惯了。we have been late already?说明迟到只是一次,并不是一种常见的现象。两句的差别是前者是一种现象了,而后者只是一次!