Question

Choose the most suitable passive voice conversion of the given sentence:
Nobody can predict future.

• A. Future cannot be predicted by anybody.
  
• B. Future could not be predicted by nobody.
• C. Future not to be predicted by somebody.
• D. Both B and C

Answer 1

Answer: (A)

Future cannot be predicted by anybody.

A sentence is in active voice when the subject is the doer of the action.
A sentence is in passive voice when the new subject (object in active voice) is the receiver of that action.
The object in the active voice now takes the place of the subject, and vice versa. (subject + verb + object, where the subject and object swap places)
The structure in the given sentence is: subject 'nobody' + verb 'can predict' + object 'future'.
Once it's changed to passive, the structure changes to:
object 'future' + verb 'cannot be predicted' + preposition 'by' + subject 'anybody'.
'Nobody' means 'not anybody', using the original word does not sound very natural in the passive voice, hence 'not' is added to the verb and the subject changes to 'anybody'.
Also, 'can (not) predict' is changed to 'cannot be predicted', since the voice changes.
This structure is seen in option A, hence it's correct.
Option B: 'Can' in the active voice is in the present tense, 'could' is the past tense form, hence B is incorrect.
Option C: The modal verb 'ca' is missing here. Instead it's replaced by an infinitive 'not to be'. Hence C is incorrect.
Option D is incorrect because options B and C are both incorrect.