"as we know it" vs "as we know"

the life [color=red]as we know it
the world [color=red]as we know it

It is regarded as a relative clause. But because of the existence of ‘it’ , how could it be an adjective clause? What part of the clause is substituted by the relative pronoun(‘as’ here)?


Hello Iwanna,

Your partial sentence refers to a particular type/manner/condition of world – i.e. the one we know. The word “as” basically means something similar to “the way in which” or “the way that”. So you might think of your partial sentence this way:

  • the world the way/condition in which we know it

The following sentences all mean roughly the same thing:

  • This is the world as we know it.
  • This is the world the way we know it.
  • This is the world that is the one we know.
  • This is the world (that) we know.

By the way, the expression “life as we know it” generally is not used with the word “the”.

  • life as we know it

[color=darkblue][size=92]“Education comes from within; you get it by struggle and effort and thought.”[/size]

Thank you very much.