Capitalization question

[darrtwish]

I'm horrible with capitalization when it comes to titles. My title is Letters to my mother...only I'm not sure how the capitalization would work.

Would it be:
Letters to My Mother?
Letters to my Mother?
Letters To My Mother?
Letters to my mother?

[FennelGiraffe]

I know 'to' should not be capitalized and 'Mother' should. I'm somewhat less certain about 'My', although I think it should be. So,

Letters to My Mother

[Mumut]

I'd say, 'Letters to my Mother'.

[Chase]

I only checked one source, Modern Lanuage Association, so there may be different opinions, but MLA echos the only rule I've ever known:

Capitalize the first letter of the first, last, and all principal words of the title.

That includes the word after hyphens.

Internal words not capitalized are articles, prepositions, coordinating conjunctions, and the "to" in infinitives.

So your title should read: Letters to My Mother.

[FennelGiraffe]

I got curious about the details and did a bit of digging. It looks like that there are some generally accepted basics, with considerable disagreement about the rest. It depends on which style guide you follow.
Always capitalize the first and last words, no matter what they are
Never capitalize (unless it's the first or last word)
articles
prepositions *,**
coordinating conjunctions
'to' in an infinitive
Always capitalize everything else, including
nouns
pronouns
verbs #
adjectives
adverbs
subordinating conjunctions ## Points of disagreement:* Some say do capitalize long prepositions, with disagreement as to what constitutes long: four or more letters vs. five or more letters.

** Some say when a preposition is part of a phrasal verb, such as turn on or give up, the preposition should be capitalized.

# A very few say don't capitalize forms of to be.

## Some say don't capitalize short subordinating conjunctions, with disagreement as to what constitutes short: three or fewer letters vs. four or fewer letters.
Alternatively, I found this rather neat rule, attributed to the U. S. Government Printing Office:"Capitalize all words in titles of publications and documents, except a, an, the, at, by, for, in, of, on, to, up, and, as, but, it, or, and nor."

[Chase]

Public response to the private message:

No, short words (such as "my") can be principal words. The other side of that is a long word, such as "between" is a preposition and as an interior word would not be capitalized.

All articles are a, an, the

A partial list of prepositions are about, above, across, after, against, along, among, around, at, before, behind, below, beside, between, beyond, by, down, during, except, for, from, in, inside, into, like, near, next, of, off, on, onto, out, outside, over, past, since, than, through, till, to, toward, under, unlike, until, up, with, without

All coordinating conjunctions are and, or, nor, but, for, yet, so.