become是不是短暂性动词

Question

我们老师说become是短暂性动词，在用于完成时态时要变成be，但是我刚才查了下become也有它的过去分词形式became，意思就是become也可以当延续性动词直接用于完成时态中啊，要不然它有过去分词是干嘛用的

Answer 1

短暂性动词是表示瞬时动作完成的意思，用于完成时不能和表示一段时间的状语用在一起，并不是不能用于完成时。
例子：
He has finished his homework.
He has finished his homework for three days.(结束不需要三天)

Now it has become a very beautiful city.
He has become a professional singer since 2005.(要改为been)

He was born in 2000,
He has been born for 8 years .(明显是不对了)