For someone (actor -um-) to test someone (loc ref -an), as to see if he can or will do something, knows something.
tumpong; tapngan
Tinapnga' hi Bukkāhan ta innilāu' hi unna nala'eng an mumbā'i ya immannung an nun'ibāagnay āatna.
I tested Bukkāhan to find out if he is knowledgeable in being a ritualist and truly he explained all about it.
Typically engaged in to find out a particular feature about someone and normally done without the subject's knowledge.
-um-: tumpong; -an: tapngan