Answer:
1.  Have you guessed the identity of the person of whom  I am speaking?
2.  It was his asking about the clock that started my  suspecting him.
3.  They – Jerry and she  - are the troublemakers.
4. Â Mrs. Van Dumont awarded the prize to Mona and me.
5. Â The counterattack was launched by Dusty and me.
Explanation: