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The girls sat on the grass looking at the setting sun.
Some girls are walking down the street talking to each other.
Someone was standing by the gate, looking at me.
My father is sitting on the sofa watching TV.

Can I rewrite those sentences into the following ones?

Sitting on the grass, the girls looked at the setting sun.
Walking down the street, some girls are talking to each other.
Standing by the gate, someone was looking at me.
Sitting on the sofa, my father is watching TV.

I'm not sure if I can rewrite them as the above examples, would you please check them out for me?
Thanks for your help!!
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The first four all need the comma; otherwise you have the grass looking at the sun.

The last four need the comma, as written. However, for some reason, they don't sound as natural to me as the first set. It may just be a case of style. Let's see what some others think.
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PhilipThe first four all need the comma; otherwise you have the grass looking at the sun.
But one of my grammar books gives this example:

My mother is cleaning the kitchen singing her favorite song.

There's no comma in it, and the book says its comma is optional. Is that sentence wrong and a comma must be added to it? Thank you for answering.
I'd appreciate any opinion, thabk you!