1) All the breakfast had been eaten before the conversation was finished. SUBJECT + PAST PERFECT + BEFORE + NOUN + PAST SIMPLE + NO AGENT 2) About four-fifths of the City was consumed by the Great Fire of London in 1666. SUBJECT + PAST SIMPLE + AGENT + TIME 3) Photographs were being taken during the ceremony. SUBJECT + PAST CONTINUOUS + DURING + NOUN + NO AGENT 4) The Queen will be met by the student delegation at the airport. SUBJECT + FUTURE SIMPLE + AGENT + PLACE 5) All main courses are served with salad or seasonal vegetables. SUBJECT + PRESENT SIMPLE + NOUN + NO AGENT 6) Lessons ought to be made more interesting for young children. SUBJECT + MODAL VERB + CLAUSE + NO AGENT
Explanation
The object of the active sentence becomes the subject of the passive sentence.
SUBJECT
VERB
OBJECT
AGENT
ACTIVE
Sarah
made
the cake.
PASSIVE
The cake
was made
by Sarah.
BY + AGENT can be omitted when the agent is unimportant, unknown, obvious from the surrounding context or words like: somebody, someone, nobody, you, she, they, people etc. They are rebuilding the house now. => The house is being rebuilt now by them. Somebody has given her twenty roses. => Twenty roses have been given to her by somebody.
