Depends on the person who is teaching and if it is a 21 word thingy or it may be a paragraph.
Jimmy studied hard for his test- He will get a good grade.
Justin did great on his homework- Justin will receive a good grade for his homework.
Practiced reading every night- She is a good reader now.
You add a comma to prepositional phrase when you want to tell more about the adjectives and adverbs.
