Times. For example, I show how change word "walk"(gulyat) with pronoun "I" (Ya)in times:
I walk / Present/ Past /Future
ya / gulyayu/gulyal(for male)/ budu gulyat
with "we"
mi /gulyaem / gulyali /budem gulyat
with "you"
ti /gulyaesh/gulyal(for male)/budesh gulyat
with "he"
On /gulyaet /gulyal /budet gulyat
with "she"
Ona /gulyaet /gulyala /budet gulyat
with "they"
Oni /gulyayut/gulyali /budut gulyat
You see in past female and male verbs different. The end "a" stand only in verbs of female only in past.