Yes, sit is a verb.
She was sitting on a red chair.He is sitting on the green mat.My friend was sitting on the coach watching tv.
Im not sitting on a chouch im sitting on a chair.
Yes, she is sitting, sitting is the Ben and she is actually doing it.
no one, i am sitting alone
Sitting on usually indicates you are on something, while at would be near or beside it. So if were on a table, you would be sitting on the table. If you were on a chair beside the table, you would be sitting at the table. Sitting at can also refer to a time something is happening, like: "The parliament is sitting at 2pm".
It depends what you are sitting on or in.
sitting
It is modelling, posing or sitting.
you are sitting .so sitting itself is doing something
The monkeys were sitting on the tree.
the bird is sitting on the tree