Question

I offered him a chair change in passive voice

Answer 1

A chair was offered to him.

OR

A chair was offered to him by me.

Answer 2

When we change into passive voice sentence will become ‘’a chair was offered to him by me’’ and in both the sentences meaning is same only structure of word changes, that in active voice subject is ‘’I’’ verb is ‘’offer’’ and object is ‘’chair’’. When it changes into passive voice object of active voice becomes subject of the passive voice which is ‘’A chair’’ and subject of active voice will become object in passive voice which is ‘’me’’ and verb will change according to the tense of the sentence.