Use of capital letters in prose. Help

[Siger]

I was wondering...Prose writers often use capital letters and ellipses in their pieces. What effects might this have?

[andsoshewrote]

Amplification, I would say...

[braindead]

Usually to place an emphasis on a particular motif and underline it as more significant than other recurring symbols. Wish I could think of an example for you but I can't - a general rule is that the writer wants to draw your attention to this thing (usually a noun) and elevate its importance, making it seem almost like a character in itself (personification, and since human characters are the central elements of most prose you will see in an exam, this makes the motif being emphasised all the more significant).

Ellipses are used to create suspense, and leave the reader guessing to some degree. They take the pace right out of reading as well - consider this:

• Jack went to the store, looking for oranges, but they didn't have oranges, only tangerines. Would Brian care if they were tangerines? He said oranges, Jack was sure, he was certain that oranges were specified, but maybe Brian was talking generally? Oh, screw it, he'd have to buy the oranges, he grabbed a bag and took them to the counter, he tapped down his pockets for his wallet, he found...
• Oh crap, he found nothing at all.

The way the pace changes is very important - the majority of that crap I made up was very fast paced, lots of commas to keep the reading as fluid and swift as possible, and in this case, created a sense of panic about oranges or tangerines - the ellipsis, when it comes, destroys this fluidity, creating an "eye of the storm" type of effect (not entirely sure if there's a literary term for this), reflecting the moment of realisation in the character.

Hope this helps!