How can I rewrite this sentence: A boy and his bog sat by a house?

bog? Do you mean "dog"?

How about ~~

A boy and his dog stood near a house.

Kathryn's sentence is awkward because the prepositional phrase (by the house) is adverbial and needs to be as close to the verb as possible, i.e., at the end of the sentence, right after the verb "stood." (If it were adjectival, you'd want it close to the subject -- but it's not adjectival!)

To rewrite the sentence "A boy and his bog sat by a house," you can make a few modifications to make it clearer and more grammatically correct. Here is one possible rewrite:

"A boy and his dog were sitting beside a house."

To get to this revised sentence, follow these steps:

1. Identify the subjects: In the original sentence, the subjects are "a boy" and "his bog." Since "bog" seems to be a typo and you most likely intended it to be "dog," you can change "bog" to "dog."
Revised: "A boy and his dog sat by a house."

2. Clarify the action and verb tense: The original sentence lacks clarity in terms of the action. Assuming you want to describe an ongoing action, you can change "sat" to "were sitting."
Revised: "A boy and his dog were sitting by a house."

3. Specify the location: The original sentence doesn't mention where the boy and his dog are sitting. You can add the word "beside" to indicate their position.
Revised: "A boy and his dog were sitting beside a house."

Following these steps, you have successfully rewritten the sentence to be clearer and grammatically correct.

By the house the boy and his dog were standing.