On the other hand this is what happens in Tagalog.
If a stem ends on a vowel, e.g. bása "read", [h] appears before a suffix :
[focused on X] b-um-ása ang X nang Y
[focus on Y] basáhin nang X ang Y
"X to read Y"
Note. Verbal suffixation makes stress move one syllable rightward.
Irregular cases, fixed by usage, have [n] instead, e.g. táwa "laugh":
[focus on X] t-um-áwa ang X sa Z
[focus on Z] tawánang nang X ang Z
"X to laught at Z"
Syncope generates forms like
kúha "take"
[focus on X] kumúha ang X nang Y sa Z
[focus on Y] *kuhúnin > kúnin nang X ang Y sa Z
[focus on Z) *kuhúnan > kúnan nang X nang Y ang Z
"X to take Y from Z"
Similar phenomena occur in nominal and adjectival derivation. (The stress
rules are different.)
e.g. táwa > táwánan "laughters of a group of persons"
úlo "head" > *ulúnan > *uhúnan > *uúnan > únan "pillow"
All this is classical Tagalog grammar.
I have discovered that in a few cases [s] is added before the suffix,
bái "woman, female" [archaic for babáe / babái] > *baisán > baysán "in-law
(on the bride's side)"