IPOS, 13 bytes
rS!r%S" le "R
Could < 10 bytes if I had implemented all the builtins that I have planned...
r # Reverse the input
S!r% # Reverse every word -> Word order is now swapped
S" le "R # insert a " le " between the two words by replacing the space
Non-competing 9-byte version
This only works with the version I pushed just now (implemented
This works by splitting the input on spaces to obtain the two words (
SC), pushing the literal
le, rotating the stack (
@) so the words are swapped and the
le is between them and finally joining the stack on spaces (
Again, could be shorter since I also plan to add commands for joining and splitting on spaces which would make this 7 bytes. But since those are probably gonna be non-ASCII characters and I haven't fully figured out the codepage I am gonna use, those have to wait a bit.