A capital letter can change the pronunciation of one word in English. Do you know what word that is? Answer at the end.
Strictly speaking, capital letters, aka upper-case letters, are not punctuation, but we'll treat them as such here. The basic rules for capitals are very easy:
1. Start sentences with a capital letter. Most word-processing programs will do this for you if you forget.
2. Use a capital letter for proper nouns. (Improper nouns don't deserve them.)
As always in English, there are exceptions. If the first word of a sentence is a proper noun that is not capitalized, you don't have to cap it here. For instance, my son Jack used "jaQ" as his musical nom de guerre. jaQ Andrews is a guitar-pickin' genius is therefore correct. As is e.e. cummings is an intriguing poet. (For foreign names that include a particle, such as Jaques de Vaillancourt, consult CMOS.)
The second rule is the one that trips people up. Not because it's hard to understand--if it's a proper noun, capitalize it--but because the definition of a proper noun is a bit hazy. In theory, it's straightforward. A proper noun is the name of a particular person, place or thing. Nikki Andrews, Pennsylvania, Legos are all proper nouns. But some nouns can be proper sometimes, common other times. Everyone has a mom. You're special, Mom. Or The doctor is ready. Thanks for your help, Doctor. When a noun is used as a name or a form of address, cap it. Some examples would be relatives (mom, dad, uncle, aunt, cousin, grampa), officials, ranks, or professionals (doctor, nurse, officer, duke, chief), endearments (honey, love, sugar).
Don't use a capital letter for occupations, even when combined with a name: writer Jessie Salisbury, architect I.M. Pei, poet Walt Whitman, district attorney Lee. Don't use them for titles that indicate rank or office, unless a name is also used: the president but President Kennedy; the sergeant but Sergeant Smith. Hint: if you can use the with the occupation, rank or office, don't capitalize.
When in doubt, check with CMOS or another reliable style manual, or your publishers usage guide. Remember that modern usage tends to minimize capitals. Next time I'll go into some more detailed examples. If you have a question or a situation that puzzles you, I'd be glad to hear from you.
Click here to listen to an excerpt from jaQ Andrews' CD Stars or Streetlamps.
Oh, and that word I mentioned at the beginning ? It's Polish/polish.