deriv LSK ETT STT aSTA ALPH OLDHOMEPAGE NEWHOMEPAGE
There are many rules relating to /thal. However, you are justified in being lazy about learning them, because (A) grammarians say the /liT should not be used to talk about events within the personal experience of the speaker, which all but bans using second person and first person forms of the /liT, and (B) those forms are also seldom found in the literature, even in the epics.
This /thal gets /iT almost always. Because of kRsRbhRvRst..., it does not get /iT after some R u ऋ उ-ender roots, as in —
**cakartha चकर्थ "you made"
and because of other sUtras, the /iT is optional after other roots —
**papaktha पपक्थ "you cooked"
**pecitha पेचिथ "you cooked"