As you probably know the passive is commonly used in English when we don’t know or don’t want to say who did something:
In Spanish we often resort to the structure ‘se’, which makes us (or rather, people from other classes…) avoid the passive in English as they are different verb patterns.
Here you are A handout on passive infinitives, which are often translated as ‘Se supone que, se sabe que, etc.) and another one on the passive_voice with quick explanations, examples and translations.
We all love listening to and watching people. Here is Jennifer ESL on youtube who is explaining the passive.
Quickly click on each link and decide which one suits you best!