afterwards可以用在句子开头吗

可以。例如：

1、Afterwards she was sorry for what she'd said.后来她后悔说了那些话。

2、Afterwards she was sorry for what she'd said.后来她后悔说了那些话。

3、Afterwards， retrospective fear of the responsibility would make her feel almost faint.后来，回想起要负的责任她几乎会吓晕过去。