deriv LSK ETT STT aSTA ALPH OLDHOMEPAGE NEWHOMEPAGE
Tenses mean the doer when they show the doer.
A /kRt affix means the doer when the resulting noun means who does the action of that affix's root. As for instance, the /zatR in **nayat- नयत् "that is leading", the /tRc in **netR- नेतृॱ "leader", the /Nvul in **nAyaka- नायकॱ "leader", and whatever affix makes the final nI नी of /grAmaNI- "village-leader", all are affixes that "mean the doer".
And of course the noun **azvas अश्वस् in the sentence **azvodravati अश्वोद्रवति means the doer of **dravati द्रवति.
The /pANini term for "when it means the doer" is /kartari.