Hell word: By

Not sure what you mean here, Phoenix. Hope I'm not answering the wrong question.

The phrase The ball was picked up Arthur doesn't makes sense in English because there is no connection between the verb and the subject of the verb. Who does the picking up? No connection between the picking up and Arthur.

It should be - The ball was picked up by Arthur. That's passive sentence construction.

'By' is the connecting word and tells us who did or performed the action (of picking up the ball).

Rephrase the sentence to an active construction - Arthur picked up the ball and the 'by' isn't needed.

I'm sure you'll get clearer answers shortly.

Goodness knows how anyone learns to speak English - actually many foreigners speak better English than the English!!

OK, but you didn't say that in your post.

By- preposition - beside, at the side of, next to

I sat beside Jim.

I sat at the side of Jim.

I sat next to Jim.

I sat by Jim.

They all mean the same thing.

Is that what you want or am I still in a fog here as to what you are asking?

"I kept it simple," he said, hoping that sounded believable.

Glad you have the answer now, Phoenix.