"We ran to each other"
-kimbia means "run (away)"
-kimbilia means "run to(wards)"
Tunakimbiana = We ran away from each other.
Tunakimbiliana. = We ran to(wards) each other.
There are quite a few instances where the applicative form (called "prepositional" in this course) changes the meaning between "to" and "from".
-hama = to move away
-hamia = to move to
And there's this weird pairing.
-pakia = to pack, put in, load, upload
-pakua = to unpack, take out, unload, download
It's not pakia vs paka because paka means "apply, smear, put on" (eg. make-up) ... this -u- is sometimes used to form opposites or sometimes more intense meanings of words.