Of course, I talk to my animals! I don't always talk to them in the same way, though. They respond to different tones and words in different ways, so I end up tailoring the way I speak to get the best response from them. It really helps me create a special bond with each individual animal.
As for what I say, the basics usually include greetings, informing them of what I'm doing, asking what they want to do (I get my answers based on their body language), reassuring them if they are scared or hurt, and telling them how much I love them over and over again.
I also sometimes use them as a sounding board for working through ideas or for venting frustrations. They are great listeners.
But I don't just talk to my pets. I talk to every animal I meet. If I pass a spider, I say "Hi" to it. If I accidentally scare a rabbit in the yard, I say "I'm sorry." I speak to the worms and caterpillars I pick up and move out of the road to tell them I'm not going to hurt them. Even if they can't understand my words, I always hope that my tone conveys my feelings.