deriv LSK ETT STT aSTA ALPH OLDHOMEPAGE NEWHOMEPAGE

/prathamA / प्रथमा

The first endings are /su /au /jas (the first group in list svaujasamauTch...). By tAnyekavac..., / su is singular, /au is dual, and /jas is plural.

These endings are used when there is no particular reason to use any others:

pacAti saH पचाति सः "he's cooking" ← saH सः has /su. Here no sUtra enjoins any case other than the first.

And also when sAmantritam applies:

he rAjAnaH हे राजानः "hey kings" / "Your Highnesses are welcome"