Q:

Change into passive voice

I have encountered a problem while converting  "This is impossible to do this" in passive voice.  What can be its passive form
Can you say "This is impossible to be done" ?? Or " it can not be done" is more correct .
Please help.

A:

First, you should not repeat 'this'.  Use "It is impossible to do this" or "This is impossible to do."
The main verb in your sentence is "is".  This is a copula and cannot be passive (nor can stative verbs like "seem").
The other verb ("do") is part of an infinitive.  One good way to make it passive is "It is impossible for this to be done."

