English is a funny language; its normal state is to be in flux. Spelling for a long time was a matter of choice and sentence structure has migrated over the years. If you don’t believe this, try reading Chaucer in the original English. Or something more recent — count how many commas (and lines) the average sentence by Jane Austen contains and then compare it to a modern novel.

Since the English language changes so much, I’m always a little reluctant to start pushing grammar rules. What’s true today may look antiquated or even be downright wrong tomorrow. However, the advantage of conforming to current standards of grammar from a marketing point of view is that it makes the piece look more polished and trustworthy. While adherence to formal grammar rules is not always necessary, it’s at least good to know the rules before you break them.

A fairly frequent grammar question is what words of a title to capitalize and what to leave lowercase. Most of us have some idea, but here are some rules for capitalization:

1) Capitalize the first and last words
2) Capitalize nouns, pronouns, adjectives, verbs, adverbs, subordinate conjunctions
3) Lowercase articles, coordinating conjunctions, “to” when it proceeds a verb, prepositions with fewer than five letters

Got all that?

These sort of lists don’t always help a lot. Some of the parts of speech most people will recognize, but some won't jump immediately to mind.

So I pulled out my trusty English grammar book, The Brief English Handbook (brief at 500+ pages), and started looking up parts of speech. What follows are abbreviated explanations. For more detailed explanations, see any good grammar book.

2) Capitalize nouns, adjectives, pronouns, verbs, adverbs, subordinate conjunctions

Nouns: Persons, places or things, e.g. Charles Darwin, France, apple
Pronouns: Take the place of a noun, e.g. we, she, he
Adjectives: Modify nouns and pronouns, e.g. the red apple (red modifies apple)
Verbs: Express action (e.g. run, dream) or state of being (e.g. is, are)
Adverbs: Most modify verbs (e.g. run quickly)
Subordinate Conjunctions: Begin dependent clauses
     The foal must learn to walk before it can leave the barn.
     “Before” is the subordinate conjunction; “before it can leave the barn” is the dependent clause. The subordinate conjunction and dependent clause modify the rest of the sentence. In this case “The foal must learn to walk” can stand on its own as a statement, but the meaning of the sentence is modified by “before it can leave the barn.”
     Common subordinate conjunctions are: after, although, because, before, if, since, so that, though, unless, until, when, where, while

3) Lowercase articles, coordinating conjunctions, “to” when it proceeds a verb, prepositions with fewer than five letters

Articles: a, an, the
Coordinating Conjunctions: There are 7 coordinating conjunctions: and, but, or, yet, for, nor, so
Prepositions with fewer than five letters
     Prepositions show the relation of a noun or pronoun to some other word in the sentence.
     He held the food over the cat
     In this case, “over” is the preposition and it shows the relationship of the cat to the food. Some common prepositions are: above, across, at, before, on, over, through, upon, within, between

Hopefully this helps sort out what to capitalize in the title. Often rules can be broken in marketing copy, especially on the internet, but it has to be done carefully and consistently or the piece will look shoddy.

If you want to learn more about grammar, Eats, Shoots & Leaves: The Zero Tolerance Approach to Punctuation by Lynne Truss is well worth picking up. It's hardly a complete review of English grammar, but it's very funny. Everyone who writes or reviews copy should also have a good grammar book like The Brief English Handbook to hand.