ぞ

英語話者に通じなきゃ意味ないぞ。

That means nothing if English speakers don't understand it.

あんないい男そうそういないぞ！！

There aren't many blokes that nice!

人(ひと)の仕事にけちをつけるのは良くないぞ？

You shouldn't be picky about other people's work, you know?

投函完了、と。後(あと)は頼んだぞ、ポストマンよ。

Mailing complete. I leave the rest to you, postman!

むしろロン毛のほうが禿げやすいって聞いたぞ。

In fact, I've heard that long hair is more likely to go bald!