They disregard social conventions without being conscious that they are doing anything extraordinary.

請問這句話中的anything能被Something替代嗎？

something用于一定句，anything用于否定句，所以大家說：

They are not doing anything extraordinary.

They are doing something extraordinary.

假如他們正在做不同一般的事情，但自己卻沒意識到這一點，大家用主從復合句，主句為否定句，但從句卻是一定句：

They are not aware that they are doing something extraordinary.

假如他們沒做不同一般的事情，他們也意識到這一點，大家用主從復合句，主句為一定句，從句為否定句：

They are aware that they are not doing anything extraordinary.

類似的例子還有：

He doesnt know he has made some mistakes.

He knows he hasnt made any mistakes.

本句中，主句They disregard social conventions 暗示他們正在某些不符合social conventions的事情，所以that從句應該是一定句。我覺得，本句中的anything不但可以改為something，而且改用something更符合整個句子的語境。

that從句用一定詞還是非一定詞，不是取決于they是不是意識到他們做還是沒做某事，而是取決于說話人覺得他們做了還是未做某事。而句首的they disregard soical conrentions 強烈暗示他們正在做某事，只不過他們沒意識到而已。that從句是個一定句，應該用一定詞something, 而不是非一定詞anything。