そんな

人前(ひとまえ)でそんなこと出来るはずもない。

There's no way I could do something like that in front of people.

そんな話(はなし)は少しも信じてはいけません。

You can't believe a word of that.

そんな不当な提案は、拒否すべきだったのに。

You should have refused such an unfair proposal.

日本人ならそんなことはけっしてしないでしょう。

A Japanese person would never do such a thing.

そんなんじゃいつまで経っても奨励賞止(どまり)まりだぞ？

With that sort of attitude you'll never get past the honourable-mention prizes.