How to change a sentece from Active to Passive

Let's start with a sentence to which we will gradually changing

Example Sentence: "The dog bit the man"

Step 1:     The dog bit the man

• Find the object of the verb. (the man)
• Make the object the subject of the new sentence.

   The man...

Step 2:     The dog bit the man

• Decide which tense the verb is in. "Simple past"
• Put the verb "to be" of this tense. (Look to see if the subject is singular o plural

The man was...

Step 3:     Bite Bit Bitten

• Write the participle of the verb after the verb "to be"

The man was bitten...

Step 4:  

• Decide if you want to include the agent in the sentence   

The man was bitten by the dog

And that is how you change a sentence from active to passive voice