It is first helpful to understand what a synonym is. It is a word that is different but has the same meaning to the previous word. Some synonyms for sad would be something like heartbroken or sorrowful, or somber or even sorry.
Like things that would symbolize sadness I would have to say, a flower in a lot of story's, letters, pictures sort of, fear, love I hope this helps this is what my teacher told me but they relate to the story's we have been reading
