Stella mailed the letter.
The letter was mailed by Stella.
The car was repaired by Mandy.
Mandy repaired the car.
The passive voice can be used if you don't know who performed the action described in the sentence.
Correct.
Sally have been married three times.
Sally has been married three times.
Gisele was invited by her neighbors to attend their party.
Passive.
A dangerous dog attacked her.
She was attacked by a dangerous dog.
A lot of coffee is grown in Brazil.
Farmers in Brazil grow a lot of coffee.
(or similar)
The passive voice cannot be used with modal verbs (should, could, can, might, etc.)
False! Modal + be + past participle is the correct structure.
The houses was built in 2008.
The house was built in 2008. or: The houses were built in 2008.
The painting was sold to Sung Ho, who later donated it to the college.
Passive.
The hunter killed the lion.
The lion was killed by the hunter.
My car is being repaired at the garage.
Mechanics at the garage are repairing my car.
(or similar)
The passive voice can be used to move the focus from the subject to the object of the sentence.
True!
That television should not was replaced. It works well.
That television should not be replaced. It works well.
Ailee is going to visit the Guggenheim Museum this summer.
Active.
Scientists wrote books about this theory.
Books were written about this theory (by scientists).
Many electronic items are made in Japan.
Factories make a lot of electronic items in Japan.
(or similar)
Is it possible to change the following sentence to the passive: "The students arrived at 7:00"?
False!
Those windows have to been washed! They look very dirty.
Those windows have to be washed! They look very dirty.
Bob was slow to finish the painting.
Active
Someone has cleaned the windows.
The windows have been cleaned.
Breakfast is served in the hotel restaurant between 7 and 10am.
The waiters/staff will serve breakfast in the hotel restaurant between 7 and 10am.
(or similar)
What kinds of verbs cannot be changed to the passive?
Verbs which do not take objects (intransitive verbs).
Some people are believed that friendly competition increases motivation.
Some people believe that friendly competition increases motivation.
The quiet cat secretly snuck up on the still and dirty rat and killed it using its paws.
Active.