Review of verb forms

[عبد القادر 32]

Explain the difference in meaning in these pairs of sentences
In my dream, a man ate a bird .I saw him do it
In my dream a man was eating a bird. I saw him doing it
I saw him cut the bird into pieces
I saw him cutting the bird into pieces
He shot at another bird. I saw him do that, too
He was shouting at another bird. I saw him doing it
Which sentences suggest most clearly that you saw a complete action from beginning to end
Which sentences could mean that you perhaps saw only part of an action and not the action from the beginning to end
Which sentence could mean that the man did the same thing more than once