sad比较级是sadder
例句
1.
There's nothing sadder to see than a picture of children who are all skin and bones.
没有什么比看到一张照片上全是皮包骨的孩子们而更难过的事情了。
2.
I think there is nothing sadder than watching a grown man listen to Eminem or Snoop Dogg in his car.
我想再没有比看到一个成年人在车里听埃米纳姆或是斯努普·多格的音乐更让人难过的事了。