In sentences with passive verbs, the subject receives the
action: it is not the "doer" of the verb's action. For that
reason, the passive is most often used when the verb and
the object are known, but the subject is either unknown
or unimportant. In situations such as this, the emphasis
is on the object.

Examples:

A cure for cancer has not yet been discovered.
(unknown subject, emphasis on the object)

Bob's car was stolen yesterday.
(unknown subject, emphasis on the object)

Tomorrow's Hint isn't yet written.
(unimportant subject, emphasis on the object)

This Hint is being created on a Mac.
(unimportant subject, emphasis on the object)

The Great Wall of China was built over 2,000
years ago. (unknown subject, emphasis on the object)

Fluorescent lamps were invented in 1938.
(unknown subject, emphasis on the object)

The modern Olympic Games have been held since 1896.
(unknown subject, emphasis on the object)

The 250th birthday of the U.S. will be celebrated in 2026.
(unknown subject, emphasis on the object)

In 1960, the Internet hadn't yet been invented.
(unknown subject, emphasis on the object)

In January 2003, the seventh anniversary of Dave's
ESL Cafe will have been observed. (unknown subject,
emphasis on the object)

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Special Notes: