It doesn't matter too much what you say at all it is ALL in how you say it. You say a lot more to your dog than you think you do and the bits that aren't spoken are probably the most important. The position of your body, how tense you are, level of eye contact and type of contact, even your heart and breathing rate will have an effect on what the dog understands. Tone and level of voice are crucial too.

Cats....well...there is one language that has passed me by!