Respective sorts things out separately, one per person, as in each team went to their respective locker rooms. Respectful describes courteous, considerate behaviour towards someone. If you can swap in the word "own" without changing the meaning, you likely want respective.
The core difference
Respective assigns something to each individual separately; respectful describes showing courtesy and regard.
- respective — belonging or relating separately to each person or thing discussed: Each employee received feedback on their respective projects.
- respectful — showing consideration, courtesy, and regard for someone or something: The students were respectful toward their teacher.
How to tell them apart
Both words trace back to respect, but they took different paths. Respective kept the older sense of "looking back at" or "regarding" each item individually, so it now signals that each person or thing in a list has its own separate version of something. Respectful is built with -ful, meaning "full of respect," and describes an attitude or manner shown towards someone.
The confusion usually shows up because both words look formal and share a root. A quick test: respective almost always sits next to a plural noun describing separate ownership (their respective offices, our respective roles), while respectful describes how someone behaves or speaks.
