Re-write the following sentences according to the instructions given after each. Make other changes that may be necessary, but do not change the meaning of each sentence.
The librarian orders books for the school library every year. (Begin: Books...)
Topic: Active and passive voice
Answer
Books are ordered by the librarian for the school library every year.
The instruction makes the object the subject, so this is a PASSIVE conversion. The original is SIMPLE PRESENT ("orders"), so the passive must be simple present too: ARE ORDERED.
Active: The librarian ORDERS books... Passive: Books ARE ORDERED by the librarian... Note "are", plural, because the new subject "books" is plural.
THE RULE THAT DECIDES EVERY VOICE QUESTION: keep the tense of the original. Simple present active becomes simple present passive.
The phrases "for the school library" and "every year" belong to neither subject nor object and simply stay where they are.