I was surprised by your behaviour. This sentence is grammatically correct.
Now,
(Active voice) The news surprised me.
In passive voice this is written as: I was surprised by the news.
I was surprised at the news of him passing the exam is grammatically correct. How? Shouldn't we use BY?
Dear student,
The adjective surprised can take at/ by interchangeably. Thus, using 'at' or 'by', both would be correct.
Regards
The adjective surprised can take at/ by interchangeably. Thus, using 'at' or 'by', both would be correct.
Regards