Чтобы преобразовать предложения из активного в пассивный залог, необходимо следовать определенным шагам. Давайте рассмотрим этот процесс на примере предложений, которые вы предоставили.

1. Определите подлежащее и дополнение. В активном залоге подлежащее выполняет действие, а дополнение - получает его. Например, в предложении "They told her the truth" подлежащее - "They", а дополнение - "her the truth".
2. Переставьте подлежащее и дополнение местами. В пассивном залоге дополнение становится подлежащим, а подлежащее можно указать в форме "by" (по). В нашем примере получится: "The truth was told to her by them."
3. Измените глагол на соответствующую форму. Глагол в пассивном залоге образуется с помощью вспомогательного глагола "to be" и причастия прошедшего времени основного глагола. Например, "told" становится "was told".
4. Обратите внимание на время. Важно сохранить временную форму. Например, "I shall send" станет "The letter will be sent".
5. Не забудьте про отрицания и вопросы. Если в активном предложении есть отрицание, то в пассивном оно также должно быть отражено. Например, "They have not yet told him about it" станет "He has not yet been told about it."

Теперь давайте преобразуем ваши предложения:

• The truth was told to her (They told her the truth).
• The letter will be sent to my aunt (I shall send the letter to my aunt).
• She was listened to attentively by everybody (Everybody listened to her attentively).
• Everything had been done before we came (They had done everything before we came).
• He has not yet been told about it (They have not yet told him about it).
• The front door was locked by somebody (Somebody locked the front door).
• An umbrella was lost here by someone (Someone lost an umbrella here).
• The boy was punished for that (They punished the boy for that).
• I was promised a book (She promised me a book).
• It will be forgotten very soon (People will forget it very soon).
• I am always waited for after lessons (They always wait for me after lessons).
• I thought the letter had already been sent (I thought they had already sent the letter).
• We could not use the tape-recorder; it was being repaired (We could not use the tape-recorder, they were repairing it).
• Her family is known to me (I know her family).
• I will be met at the station (They will meet me at the station).
• The windows were not left open (I did not leave the windows open).
• The newspapers said that the interesting exhibition would be opened next week (The newspapers said that the interesting exhibition (to open) the next week).
• This bone will be given to my dog tomorrow (This bone (to give) to my dog tomorrow).
• They will be met in the hall (She (to meet) them in the hall).
• He was told to prepare a speech yesterday (Yesterday he (to tell) to prepare a speech).
• Budapest is divided by the Danube into two parts (Budapest (to divide) by the Danube into two parts).
• This new dictionary is sold everywhere now (This new dictionary (to sell) everywhere now).
• Interesting information about the life of the USA can be found in this book (You can (to find) interesting information about the life of the USA in this book).
• Nick will be sent to Moscow next week (Nick (to send) to Moscow next week).
• We were invited to a concert last week (We (to invite) to a concert last week).
• Your luggage will be brought to your room by the porter (The porter (to bring) your luggage to your room).
• She is often spoken about at school (She often (to speak) about at school).
• The article was published last week (The article (to publish) last week).
• Moscow was founded by Uriy Dolgorukiy in 1147 (Uriy Dolgorukiy (to found) in Moscow in 1147).
• All the texts were looked through yesterday and not a single mistake was found (All the texts (to look) through yesterday and not a single mistake (to find)).
• Her cake was baked very well (She baked her cake very well).
• This book will be translated next year (They will translate this book next year).
• This little boy was not noticed by anybody (Nobody took notice of this little boy).
• He had evidently been informed of the news before they announced it (Evidently somebody had informed him of the news before they announced it).
• I am sure they will be pleased by your parents (I am sure your parents will please them).
• The sick man should be sent to hospital (You should send the sick man to hospital).
• He was a brilliant speaker, and, whenever he spoke, he was listened to with great attention by the audience (He was a brilliant speaker, and, whenever he spoke, the audience listened to him with great attention).
• I remember that the tickets have been paid for (I remember that we have paid for the tickets).
• The house was built in 1960 (They built the house in 1960).
• You will be told when to come (They will tell you when to come).
• The boat was lost sight of in the fog by everybody (Everybody lost sight of the boat in the fog).
• Some new metro lines are being constructed now (They are constructing some new metro lines now).
• I was informed that you had been seen in Oxford Street (They informed me that they had seen you in Oxford Street).
• Why was he laughed at? (Why did they laugh at him?).
• All the dry leaves were gathered by the gardener (The gardener gathered all the dry leaves).
• Their work was finished in time (They finished their work in time).

Следуя этим шагам, вы сможете успешно преобразовать предложения из активного в пассивный залог. Удачи в обучении!