-om-
To sniffle, as with a cold or when one has been crying.
singhot
Pirmiang sisingot-singot, aggalobangena?
You're always sniffling, do you have a cold?
-on
To sniff something in order to smell it.
Masabor ang singoton tang belat ang mabanglo.
It's nice to sniff rice that smells good.
Ono si siang agsingoton mo?
What is that that you are
sniffing
at again?