一直是的用法和样例：
例句
-
我一直是每天工作12小时，不过我再也坚持不住了。
I've been working twelve hours a day, but I shall not be able to keep it up. -
那当然是约翰的妈妈。我差点把她给忘了。她一直是咱们的好朋友，对吧？
And that's John's mum, of course. I'd almost forgotten her. She's been a good friend to us, if you like. -
事情一直是这样，并将继续这样下去。
It has been thus and will continue to be so. -
我妹妹一直是一个勤奋的学生。
My sister is always a studious student.
