[Grammar] Doing two actions at the same time.( I'm lying about doing nothing)

[saloom2]

Hello everyone,


I'm a bit confused with this sentence. should a verb after another one be v+ing without a comma?(Doing two action at the same time) So, why is the comma used in this sentence?

Oh, I've been up all night, finishing my essay. Copied from here.

 

[Rover_KE]

The comma is optional in that sentence.

 

[saloom2]

But why did the writer use it? I want to know exactly why it's optional. Thanks.

 

[Rover_KE]

If you said that in conversation, you may or may not pause momentarily after 'night', depending on whether or not you felt it necessary to explain why you were up all night.

In the written form, the comma reflects that momentary pause.