The way an engine works has never been understood by David. Changes the passive voice to the active voice or the active voice to the passive voice.

David has never understood the way an engine works.

The active voice sentence would be: "David has never understood the way an engine works."

The passive voice sentence would be: "The way an engine works has never been understood by David."

To change the passive voice to the active voice or vice versa, you need to understand the basic components and structure of a sentence.

In the active voice, the subject performs the action of the verb, while in the passive voice, the subject receives the action of the verb. Let's apply this concept to the given sentence:

Original sentence: "The way an engine works has never been understood by David."

Passive to active voice conversion:
1. Identify the subject: "The way an engine works"
2. Determine the verb: "has never been understood"
3. Identify the doer (agent): "by David"

Now, let's convert it to the active voice:
"David has never understood the way an engine works."

Active to passive voice conversion:
1. Identify the subject: "David"
2. Determine the verb: "has never understood"
3. Identify the receiver (patient): "the way an engine works"

Now, let's convert it to the passive voice:
"The way an engine works has never been understood by David."

Remember, when changing the voice, it's essential to maintain the meaning and structure of the sentence while altering the subject and verb relationship.