An active voice sentence:
The professor is teaching the students.
A passive voice sentence:
The students are being taught by the professor.
Be (am, are, is, etc.) or Get + past participle of the verb
What is a past participle?
Example: "stolen" is the past participle of "steal";
"spoken" is the past participle of "speak";
"seen" is the past participle of "see";
"taken" is the past participle of "take".
In Chinese, the passive voice construction is: 被 + Verb (because the verbs in Chinese don't change forms.)
Examples: My wallet was stolen. 我的钱包被偷了。
My paper got ripped. 我的纸被撕掉了。