So, can a student pilot apply any flight time he or she logged while training for a sport pilot certificate toward a private pilot certificate? According to a letter from the FAA's Office of the Chief Counsel to aviation journalist Tim Kern, who queried the office, solo sport pilot flight time may only be credited to solo private pilot flight time if the "specific category and class of aircraft are met." Logging instruction time depends on the instructor's credentials. If instruction is received from an instructor who holds only a a sport pilot rating, that instruction may not be credited toward the issuance of a private pilot certificate. However, if the instruction toward a sport pilot certificate is provided by an instructor authorized to provide instruction to both sport pilots and private pilots, that time could "be credited toward the flight training requirements for a corresponding private pilot certificate." There are more details ... .
This is a companion discussion topic for the original entry at https://www.avweb.com/news/faa-light-sport-time-can-go-toward-private-cert-sometimes