其实这句话顺序应该是这样:
To lift is too heavy for me.
成分:to lift (真正主语)
is (谓语be动词)
too heavy (表语)
for me (介词短语)
it is在这里只是作为形式主语
有时主语太长,可用it作形式主语,将真正主语放在后面.如：
It is fun swimming in a river or lake in summer.