1.

I am sad to hear the news about the death of your grandfather.

(Traditional) 我聽到你爺爺去世的消息(關於你爺爺的去世),我感到很難過。

(Simplified) 我听到你爷爷去世的消息，(关于你爷爷的去世),我感到很难过。

* 爺爺(dad's dad)//爷爷，外公(mom's dad)

奶奶(dad's mom)，外婆(mom's mom)

feel 覺得，感到(more formal)//觉得，感到

sad 難過，傷心(heartache)//难过，伤心

2.

The gravitational-wave "revolution" is underway.

(