Answer:
I go around in circles, but always straight ahead, never complain, no matter where I am led.
I go up and I go down, towards the sky and the ground. I’m present and past tense too, let’s go for a ride, me and you. What am I?
Walk on the living, they don’t even mumble. Walk on the dead, they mutter and grumble. What are they?
Some will use me, others not. Some have remembered, others forgot. For profit or gain, I'm used expertly. I can't be picked off the ground or tossed into the sea. What am I?
I am a creature with a “tight” name.
If it’s information you seek, come and see me. If it’s pairs of letters you need, I have consecutively three. What am I?