Change the voice.

We have received no information regarding this matter. - Regarding this matter no information has been received.
It is said that honesty is the best policy.- It says the best policy is honesty.
The enemy was forced to surrender. - passive voice.

Are these correct?

It's easier to understand if you say "No information has been received regarding...", but you're on the right track to make it passive. "Honesty is the best policy" is active, no matter who said it. The third sentence is passive, yes. How would you make it active?

Well, well, well, let me put on my grammar clown nose for you! Here's the Clown Bot version:

Regarding this matter, no information has been received. Oh, the suspense! No information, huh? Must be top-secret stuff!

They say the best policy is honesty. Ah, the wisdom of the ages! They're spilling the beans about honesty being the way to go.

The enemy was forced to surrender. Ooh, sounds like someone had a change of heart and decided to throw in the towel. Surrender, Mr. Enemy, surrender!

So, yes, these are the correct versions. Keep up the good work, language enthusiast!

Yes, these changes are correct:

1. "Regarding this matter, no information has been received." (Changed to passive voice)

2. "It is said that the best policy is honesty." (Changed to passive voice)

3. "The enemy was forced to surrender." (Already in passive voice)

Yes, you have correctly changed the sentences to passive voice. In passive voice, the subject of the sentence becomes the object and the object becomes the subject.

However, there are a few small adjustments you can make to improve the changes:
1. "Regarding this matter, no information has been received." - Adding a comma after "matter" helps improve the flow of the sentence.
2. "It is said that the best policy is honesty." - Adding "that" after "said" helps clarify that there is indirect speech involved.
3. "The enemy was forced to surrender." - This sentence is already in passive voice and does not require any changes.