可能是
THERE BE句型的衍生：谓语BE变为HAVE/HAS BEEN；“（此处/某处）已经有过/曾经有过****”的表达.
至于后面的ADJ.,还真没啥印象；估计楼主断章取义了,比如说：there have been many changes in my life.中的several就是形容词,但是它是修饰chages(in my life)的.