I see sleep turtle.
something that I would do
Is there any native England here? Why is sleep not sleeps? The turtle is a singular noun, isn't it?
It’s because “sleep” is modifying like an adjective.
I see/watch the child eat.
He sees/watches the bird fly.
And why is it not sleeping?
Adjective is a poor way to define it. Subordinate clause is better.
It's sort of like a sub-sentence that has its own conjugation.
I would say, I watch the turtle sleeps.
No. The turtle sleeps. We watch it sleep. Sorry i cant offer a good reason!