ok, so i'm pagan, and i was wondering-- how can i be sure which deity is speaking to me? im pretty sure, but how can i be certain?

okay so first yiu has to be sure that your talking to deitys.,

Sudden numbness or weakness in the face, arm, or leg, especially on one side of the body.
Sudden confusion, trouble speaking, or difficulty understanding speech.
Sudden trouble seeing in one or both eyes.
Sudden trouble walking, dizziness, loss of balance, or lack of coordination.
Sudden severe headache with no known cause. ...

and u should be speaking to some deities soon

fuk, deity's*

I would research what deities usually correspond with historically, it will usually be related to that. For example if you were a Norse Pagan and work with Odin and you see crows outside of their migratory period then he could be trying to get your attention. Its not always a surefire way though because Bacchus once came to me as the "angel of wine and good times" in a judeo christian context (i was raised in the church and thus familiar with christian iconography) so it may also be personal to you as well. I'd sit and meditate as well, see if any come to you—only if you know about warding and protection though, fae can be douchebags lol