There’s a regular module I do at one school on writing about processes coming up soon. So a focus here is on use of passive clauses in such contexts. For years I was happily ignorant, induced by inaccurate instruction from books, about this grammar area. So it was a blessing to read and watch noted linguist Geoffrey Pullum pull apart such advice.
As an exercise for me to try to remember his counsel I knocked up three infographics, some work better than others. The information for these graphics come from Fear and Loathing of the English Passive (html); the 6 part video series Pullum on Passives and On the myths that passives are wordy (pdf).
Types of Passives
Real rules for Passives
Allegations against Passives
Note that Pullum is not really impassive more impassioned but that makes the title of this post less groovy : )
Hope these are of use to you, thanks for reading.