Answer:
Run-on sentence mistakes occur when two or more independent clauses are not linked correctly.
Run on sentences are divided into fused sentence (two independent clauses are together without any sign of punctuation or coordinating conjunction that divides them) and comma splice (two independent clauses joined just by a comma).
Step-by-step explanation:
Fused sentence (no linking word or punctuation mark separating the independent clauses before “he was motivated”): He won the U.S. championship at age 14 he was motivated to train hard for the Olympics.
Fused sentence (no linking word or punctuation mark separating the independent clauses before “his father”): Out of shape, he finished last in the Olympic trials his father, Yukio, was disgusted and desperate.
Comma splice (only comma separating independent clauses, a linking word should be added after the comma): It had food and heat but no phone or television, he told Apolo to think about what he wanted to do.
Fused sentence (no linking word or punctuation mark separating the independent clauses before “he told”): Apolo decided to get serious about his life and his skating he told his father that he didn't want to end up like his friends in Seattle.
Comma splice (only comma separating independent clauses, a linking word should be added after the comma): His hard work paid off in Salt Lake City, he won the gold medal in the 1500-meter event and silver in the 1000-meter.