Someone (mag-, mangi-) prepares something (i-) for someone (i--an) or something (-an).
sagána
handâ
Magsagāna tas ichan.
Let's prepare a viand (for supper).
Aba polos chapatak namen, as dawa magsagsagāna kami aba.
We absolutely did not know, so we did not prepare (for the storm).
Mangisagāna ka so karga.
You prepare the cargo (to go).
Isaganāan ko kangay no bisīta.
I prepare for the coming of the visitor.