An or on is used when the root ends with a consonant or a vowel with a grave or angular accent.

An h preceds them when the roots ends with a vowel otherwise accented or non-accented, or pronounced separately from the preceding consonant or consonants.

The particle an or han is simply added to the root, as,

from

catúrog (to sleep), caturogán (sleeping place);
sing̃ba (to adore), sing̃báhan (church);
taclob (to cover), taclóban[17] (covering place);[[16]]
tan-ao (to see at a distance), tan-aoan[18] (watching place);

or is employed either with the interfix r combined with the first vowel of the root or with the first consonant and vowel of the root instead, as

from

cáon (to eat) caraonán

from

tíroc (to assembly) titiroeán (meeting place);