deriv LSK ETT STT aSTA ALPH OLDHOMEPAGE NEWHOMEPAGE
Coulson says this about the consonant /liT (/thal /va /ma /se''' /vahe''' /mahe''') —
They get /iT more often than not, even after /aniT roots.
There is no /iT after few R ऋ-u उ-enders. Those are listed in kRsRbhRvRst.... ( **cakRma चकृम, **zuzruma शुश्रुम).
In the case of /thal, the /iT must be omitted in other verbs too, and is optional in others.
One of the optional itha इथ roots is pac पच् —
**papaktha पपक्थ "you cooked"
**pecitha पेचिथ
itha इथ is always optional after A आ-enders —
**dadhAtha दधाथ "you gave"
**dadhitha दधिथ "you gave"
See also summary of liT ending changes.