1. With night coming on, we started for home.

2. Because night came on, we started for home.

3. Night came on, and we started for home.
(Does #1 mean #2 or #3?)

4. With his legs crossed, he read a book.

5. His legs were crossed, and he read a book.
(Does #4 mean $5?)

Yes, 1, 2, and 3 all mean the same thing.

Also, 4 and 5 mean the same thing.

Nice job!

1. With night coming on, we started for home: This sentence means that as night was approaching, we began our journey back home. The phrase "with night coming on" is a description of the situation in which the action of starting for home takes place. In this sentence, it implies that the reason for starting the journey was the approaching night.

2. Because night came on, we started for home: This sentence means that we started our journey back home because night arrived. The word "because" indicates a cause-and-effect relationship, conveying that the reason for starting the journey was the onset of night.

3. Night came on, and we started for home: This sentence means that night arrived, and immediately after, we began our journey back home. The conjunction "and" connects the two actions, indicating a chronological sequence. The sentence implies that the start of the journey occurred directly after the onset of night.

So, #1, #2, and #3 have similar meanings, with slight differences in emphasis and sentence structure.

4. With his legs crossed, he read a book: This sentence means that while having his legs in a crossed position, he engaged in the activity of reading a book. The phrase "with his legs crossed" describes the manner in which he performed the action. It emphasizes the simultaneous nature of the two actions.

5. His legs were crossed, and he read a book: This sentence means that his legs were already crossed before he began reading a book. The conjunction "and" connects the two separate details without implying a direct cause-and-effect relationship. The sentence suggests that his legs were already in a crossed position before he started reading.

So, #4 and #5 have similar meanings but slightly different structures.