[<< wikibooks] Sanskrit/Verbs
present tense, parasmaipada
the verb is formed by putting a personal affix on the verbal root, sometimes using an infix.
endings:

ti, tha, nti
si, thah, tha
ami, avah, amah-ति, -थ, -न्ति
-सि, -थः, -थ
-अमि, -अवः, -अमःinfixes: 

1P: -अ-
4P: -य-
10P: -अय-for verbs in the 1, 4, and 10 class, the vowel in the verbal root is strengthened to its gunah substitute, eg:
तृ (1P) (to cross over) -- to form the 1st person singular, we convert "ऋ" to "अर्", giving "तर्".  we then add the infix for 1P verbs, "-अ-", to get "तर".  then we add the 1st person singular ending, "ति" to get the conjugated verb, "तरति" ("he crosses over").
गम् (1P) (to go) -- to form the 3rd person singular, we convert "गम्" to "गच्छ्".  we then add the infix for 1P verbs, "-अ-", to get "गच्छ". we then add the postfix "अमि" to get the conjugated form "गच्छामि".
चुर् (10P) (to steal) -- to form 1st person plural, we change "चुर्" to "चोर्", then add infix "-अय-" and termination "-न्ति" to form "चोरयन्ति" ("they steal").