Have I made the following sentences correctly?

[Nathan Mckane]

Have I made the following sentences correctly?

You have pulled off a grammatical sentence.

That's where you are off the mark.

According to the law, you will be sentenced for 5 years without parole.

When in circle of friends, be polite and unassuming.

Thanks.

[emsr2d2]

Have I made the following sentences correctly?

You have pulled off a grammatical sentence.

This doesn't really make any sense. You "pull something off" by succeeding at it against the odds, but I get the impression that you mean that the person has simply written a sentence. "Pulled off" seems a little extravagant for this! I'm also not sure what you mean by a "grammatical sentence". Do you mean a "grammatically correct sentence"?

That's where you are off the mark.

Fine.

According to the law, you will be sentenced for 5 years without parole.

You will be sentenced to five years...

When in circle of friends, be polite and unassuming.

When with a circle of friends, ...
When you are with a circle of friends...
When with your circle of friends...

When you say "in a circle of friends" do you mean that you are simply part of someone else's circle of friends, or that you are actually physically with them?

Thanks.

See above.

[Nathan Mckane]

Special thanks for your comprehensive answers.

I meant physically.

[emsr2d2]

Special thanks for your comprehensive answers.

I meant physically.

In that case, use "with" a circle of friends. Or simply "with friends".