In Cambridge dictionary I saw a sentence:
They sat in the back row of the cinema kissing and cuddling.
As a basic learner I always would use:
They were sitting in the back row of the cinema kissing and cuddling.
Like:
I was sitting there doing nothing.
Can I use:
"I sat there doing nothing."
Instead?
Please explain.
Thank you.
These are all correct. However, "is" and all of its forms are considered a weak verb, and it creates a wordy sentence.
Eliminating "is" results in a more concise and active statement, which is usually desirable unless something more important is going to happen in the sentence. For example,
I was sitting there doing nothing when an airplane engine crashed through the ceiling.
The "doing nothing" is describing the subject's state and there's no problem to bring it with either of the two tenses. Simple past expresses doing something, namely an action, while past progressive describes the state of the subject (how the subject was, in this case, sitting).
