Instructor Responsibilities and Professionalism
What the instructor owes the learner
Core responsibilities are to help the learner learn by adapting to the individual, provide adequate instruction that is thorough and current, demand adequate standards by refusing to sign off marginal performance, emphasize the positive, and minimize learner frustration. Instructors also counsel learners on progress and options, keep accurate records and endorsements, and model safe behavior at all times.
Professionalism is observable: sincerity, acceptance of the learner as a person, personal appearance and habits, demeanor, proper language, and consistent safety practices. It includes self-improvement, staying current with regulations, technology, and teaching technique, ethical conduct, and putting the learner's welfare ahead of the instructor's ego or convenience.
Endorsements and records are legal acts. You may not endorse a learner for a knowledge test, practical test, or solo flight until you have given the required instruction and seen evidence of proficiency. The logbook signature duties and prohibitions are in 14 CFR 61.189. Signing off someone you did not train, or who is not ready, breaches trust and often breaches regulation.
Traps: adequacy of instruction and demanding adequate standards sound alike but are different, one about depth and currency, the other about holding the bar. Also expect "which is a professional responsibility" items in which a distractor is actually an instructor privilege.
Worked example: a learner asks for a practical test endorsement after one weak lesson. The professional response is more instruction with specific objectives, never a signature. Rule of thumb: never certify what you have not observed.