Although the verb be is the traditional auxiliary verb used to form the passive voice, many native English speakers also use the verb get when forming passive sentences. For example:
- The cookies were eaten. (be)
- The cookies got eaten. (get)
- My coworker is being disciplined. (be)
- My coworker is getting disciplined. (get)
- The bathroom had been cleaned. (be)
- The bathroom had gotten cleaned. (get)
- Vegetables have been being stolen. (be)
- Vegetables have been getting stolen. (get)
Note that the verb get can only replace the be that directly precedes the past participle. Therefore, while the use of get in have been getting stolen is grammatically possible, the use of get in *have gotten getting stolen is not. (The asterisk * indicates an incorrect example.)
The difference between the use of the verb be and the use of the verb get in the passive voice is, like in most linguistic situations in which multiple forms are possible, a matter of style rather than grammatical correctness with be being more formal and get being less formal. For example, most native English speakers would only ever write was eaten in an academic essay but often say and hear got eaten in casual conversation.