I have an 8 year old american bulldog (scott, looks like a pit) that is super highly trained in a variety of tasts...
Sit - he just looks at you, unless you have treats.
stay - he actually does.. if he wants to
speak - he just looks at you
come - he just looks at you, unless he wants attention
attack - he just looks at you
paw (or high five) - he sits, because he thinks youre going to give him a treat
roll over - he just looks at you
play dead - he does just fine, but while looking at you
hike, and ride, gets him into a frenzy
funny thing is other dogs on the hiking trail or at the park wont let their dogs near him because he looks like a big beast. My 2 yo nephew lets buster drag him all over the house by hanging on his harness :)