Stappenplan Active->Passive
1) Read the original sentence: who does what (= subject verb object -> John reads books).
2) What tense is it in? (reads = present simple)
3) Now turn this into a passive sentence: what is done by whom (= object verb subject -> The books are read by John)
4) Make sure you keep the form of TO BE in the same tense as the tense of the verb (pv/finite form) in the original active sentence (reads = present simple -> so the form of "to be" needs to be "am, is or are"
5) Check if the object is singular or plural and use the correct tense of to be & the correct form (books = plural; the tense is present simple; the form of "to be" in the present simple and in the plural form = are)