Change the sentences into passive voice (Present Simple Passive, Past Simple Passive, Future Simple Passive) He doesn't write the letters.
We planted the trees last year.
She designs the dresses
My friend will bring the book next week.
Mother will wait for guests tomorrow.
People used telegraphs in the past.
Company builds new houses every year.
Children visited the museum last week.

"He doesn't write the letters" can be changed into passive voice as "The letters are not written by him."
Explanation: In the original sentence, the subject "He" is performing the action of "writing the letters." In passive voice, the subject becomes the receiver of the action and is preceded by the verb "to be" in the corresponding tense. The object "the letters" becomes the subject and the verb "write" is changed to its past participle form "written." The negative form "doesn't write" is changed to "are not written" to maintain the negative meaning.

"We planted the trees last year" can be changed into passive voice as "The trees were planted last year."
Explanation: In the original sentence, the subject "We" is performing the action of "planting the trees." In passive voice, the subject becomes the receiver of the action and is preceded by the verb "to be" in the corresponding tense. The object "the trees" becomes the subject and the verb "plant" is changed to its past participle form "planted."

"She designs the dresses" can be changed into passive voice as "The dresses are designed by her."
Explanation: In the original sentence, the subject "She" is performing the action of "designing the dresses." In passive voice, the subject becomes the receiver of the action and is preceded by the verb "to be" in the corresponding tense. The object "the dresses" becomes the subject and the verb "design" is changed to its past participle form "designed."

"My friend will bring the book next week" can be changed into passive voice as "The book will be brought by my friend next week."
Explanation: In the original sentence, the subject "My friend" is performing the action of "bringing the book." In passive voice, the subject becomes the receiver of the action and is preceded by the verb "to be" in the corresponding tense. The object "the book" becomes the subject and the verb "bring" is changed to its past participle form "brought."

"Mother will wait for guests tomorrow" can be changed into passive voice as "The guests will be waited for by mother tomorrow."
Explanation: In the original sentence, the subject "Mother" is performing the action of "waiting for guests." In passive voice, the subject becomes the receiver of the action and is preceded by the verb "to be" in the corresponding tense. The object "guests" becomes the subject and the verb "wait" is changed to its past participle form "waited for."

"People used telegraphs in the past" can be changed into passive voice as "Telegraphs were used in the past by people."
Explanation: In the original sentence, the subject "People" is performing the action of "using telegraphs." In passive voice, the subject becomes the receiver of the action and is preceded by the verb "to be" in the corresponding tense. The object "telegraphs" becomes the subject and the verb "use" is changed to its past participle form "used."

"Company builds new houses every year" can be changed into passive voice as "New houses are built every year by the company."
Explanation: In the original sentence, the subject "Company" is performing the action of "building new houses." In passive voice, the subject becomes the receiver of the action and is preceded by the verb "to be" in the corresponding tense. The object "new houses" becomes the subject and the verb "build" is changed to its past participle form "built."

"Children visited the museum last week" can be changed into passive voice as "The museum was visited by children last week."
Explanation: In the original sentence, the subject "Children" is performing the action of "visiting the museum." In passive voice, the subject becomes the receiver of the action and is preceded by the verb "to be" in the corresponding tense. The object "the museum" becomes the subject and the verb "visit" is changed to its past participle form "visited."