This chapter is about habit. As Samuel Beckett once noted, "Habit is the ballast that chains the dog to his vomit.” It is amazing how consistently we repeat the exact same little errors out of mere habit. However, we can tackle these habits by identifying them as patterns and writing with an eye for them. As a graduate student, I once misspelled the word "separate” (using an "e” in the middle) 16 times on an exam. My professor circled the offending letter each time and glibly noted, "I wish you could spell better.” His chiding cured me, and (knock wood) I have not misspelled "separate” since. Many students find that they have picked up the habit of putting commas in automatically before prepositions or even after conjunctions rather than before. Once such habits are identified, however, they can be addressed effectively.
No matter how niggling they may seem, details about punctuation, mechanics, capitalization, and spelling are important to master. Even with the spell checker and grammar checker eternally activated, we can make plenty of tiny mistakes that deeply affect sentence meaning. I know of an engineer who has repeatedly reported inaccurate dollar amounts to clients because of his sloppy proofreading. I have read government reports by well-published scientists where the colon was misused more than a dozen times in a single report. Even capitalization rules can be highly important to meaning: a student in geology, for example, must be aware of whether or not to capitalize "ice age” (yes when you mean the specific glacial epoch; no when you mean any of a series of cold periods alternating with periods of relative warmth). Finally, small mechanical errors (such as abbreviating a term or acronym improperly) reflect a general sloppiness and disregard for convention.
So work on the little things. Seek to understand punctuation marks as units affecting grammar and meaning, and accept proper spelling, capitalization, and mechanics as professional necessities. This chapter will help you to do so without immersing you into a grammatical swamp.
For further lessons on punctuation, visit these pages: