Are you talking about the present, passive, active? If so then I hope this helps:
To form it you take the stem (infinitive minus the -re) and add these endings:
In Enlish we have two ways of saying the present passive. For example with the verb "to carry":
I am carried, I am being carried
you are caried, you are being carried
He is carried, he is being carried
In English these forms require a form of the verb "to be" as auxiliary (helper) verbs. It does not mean that to translate English into Latin you need to use "esse".
Portor = I am being carried, I am carried
Portori = You (s) are being carried, You (s) are carried
Ab femina portor.
I am being carried by the woman.
Does that help? Any more questions?