Taylor was usually a cheerful boy, but today he looked solemn, and I wanted to know what was going on.
Solemn means "serious", so you could say "when he told me of my friend's death, he looked very solemn".
As I walked out of the cany shop into the rain without my chocolate bar, i felt very solemn.
Solemn means serious. "The funeral was a solemn occasion for our family." "He made me a solemn promise he would not reveal the secret to anyone."
That funeral was the first solemn occasion in my life.