It may be that much harder to change to a more constructive behavior 句中,that 应该是引导一个句子吧?但 that 之后并无主语。如果是从句,那先行词是 it 吗?
这里的 that 不是连词(不是引导从句),而是副词,相当于 so。又如:
He’s not that rich. 他没那样有钱。
It isn’t all that cold. 天没那么冷。
I wasn’t that clever. 我没有那么聪明。
It’s about that long. 大约有那么长。
It isn’t that funny. 没有那么好笑。
He didn’t look that bad. 他看上去没那么坏。
I don't have that much money on me. 我身上没带那么多钱。
He wasn’t all that much older than we were. 他当时并不比我们大多少。