In Mandarin Chinese it is very easy to express the active and passive voices. If you aren’t very familiar with grammar and what that means here are some examples in English
The boy ate the chicken
The chicken was eaten by the boy
The chicken was eaten
The first sentence is active voice. It is the most common way of speaking. But sometimes we want to direct more attention to the object (in this case the chicken) and that’s when we need passive voice. Especially in the 3rd sentence when we don’t necessarily know WHO ate the chicken, but we do know it was eaten by someone. For such sentences passive voice is a must.
In Mandarin Chinese we use “ba” 把 (3rd tone) and “bei” 被 (4th tone) for active and passive voice. In fact with active voice we don’t even need “ba” 把 as it can be expressed using grammar similar to English. However if you want to speak idiomatically (ie the way a native Chinese person would speak) then you should learn to use “ba”.
Using English I will show you where to place “ba” and “bei” for the 3 sentences above :
The boy “ba” 把 the chicken eat
The chicken “bei” 被 boy eat
The chicken “bei” 被 eat
You will notice each time I rendered the verb as “eat”. I didn’t change it to “ate” or “eaten”. I do this on purpose to demonstrate that the verbs in mandarin never change for any reason. It sounds horrible in English of course, but it’s perfect grammar in Mandarin.
You will also notice that in each sentence the verb is at the end. This is because this is how the Chinese speak. They like to have all their nouns or objects at the beginning of the sentence and verbs towards the end.
You could also say in mandarin “the boy ate the chicken” the same as we say in English. The word order and grammar is the same but you don’t need to use “ba” here. You only use “ba” when you want to mention the 2 objects before the verb (which is a more authentic way to speak in chinese).
Another way I like to think of “ba” and “bei” is like direction arrows.
把 ba ->
被 bei <-
So whatever is in front of “ba” is performing the action to the thing after “ba” 把, and of course “bei” 被 is the opposite.
Here are some more sentences where “bei” would be used (ie passive voice)
The criminal was arrested
The man was beaten
The water was drunk
The door was opened by me
I am loved
All of the above sentences would use “bei” in mandarin.