Avoiding run-on sentences

English

What is the subject of this sentence? 'The naughty dog stole some sausages from the trolley.'

Which part of this sentence tells us when it happened? 'I will finish my homework after I have eaten dinner.'

Which of these is a correct past tense verb?

I was really tired last night and I went to bed early.

I was really tired last night I went to bed early.

I was really tired last night. I went to bed early.

I was really tired last night. Went to bed early.

There be three foxes in our garden yesterday morning.

There is three foxes in our garden yesterday morning.

There was three foxes in our garden yesterday morning.

There were three foxes in our garden yesterday morning.

Shelley drove to the supermarket and bought a new washing machine.

Shelley drove to the supermarket and she bought a new washing machine.

Shelley drove to the supermarket and Shelley bought a new washing machine.

Shelley drove to the supermarket. And she bought a new washing machine.

She ate a big breakfast. It was delicious.

She Ate a Big Breakfast. It was Delicious.

She ate a big breakfast. It were delicious.

Margaret flew first class to Australia. It is so comfortable.

Margaret flew first class to Australia. It so comfortable.

Margaret flew first class to Australia. It was so comfortable.

Margaret flew first class to Australia. So comfortable.