Comment by Kamil Maciorowski on How to delete a file as long as another file with the same name but a different extension of it exists?

(1) Must, may or mustn't the solution work in subdirectories? (2) The -r in rm -r only matters if the operand is a directory. You did think about -r. Does this mean that some directories match *.mkv and the solution should remove them conditionally like regular files? (3) Any question should show reasonable research effort. What have you tried? Where are you stuck?