Does the following sentence have an antecedent? If so, where?: Steve works very hard, unfortunately Sam does not do the same.
"The same" refers to works.
The same is an adjective and pronoun too.
By grammar morphology, we can say we can use adjective too as it refers to previous noun---works.
Like, he is extraordinary.
We know in general situation adjective modifies noun before putting itself. But adjective could be put after the main verb and noun,like--here is, it indicates the noun that is previously indicated---he, pronoun usage, a noun/pronoun, both noun/pronoun could be subject and object.
Hope you understand the morphology.