David Foster Wallace’s 2002 Pomona College handout on five common word usage mistakes for
his advanced fiction writing class:
ENGLISH 183A, 25 SEPTEMBER 2002—YOUR LIBERAL-ARTS $ AT WORK
1. The preposition towards is British usage; the US spelling is toward. Writing towards is like
writing colour or judgement. (Factoid: Except for backwards and afterwards, no preposition
ending in -ward takes a final s in US usage.)
2. And is a conjunction; so is so. Except in dialogue between particular kinds of characters, you
never need both conjunctions. “He needed to eat, and so he bought food” is incorrect. In 95% of
cases like this, what you want to do is cut the and.
3. For a compound sentence to require a comma plus a conjunction, both its constituent clauses
must be independent. An independent clause (a) has both a subject and a main verb, and (b)
expresses a complete thought. In a sentence like “He ate all the food, and went back for more,”
you don’t need both the comma and the and because the second clause isn’t independent.
4. There are certain words whose appearance at the beginning of a clause renders that clause
dependent. (They basically keep the clause from expressing a complete thought.) Examples
include since, while, because, although, and as. You may have learned to call these kinds of
words Signal Words or Temporal Adverbs in high school. They, too, affect the punctuation of a
compound sentence.
The crucial question is whether the clause that starts with a Signal Word occurs first in the
sentence or not. If it does, you need a comma:
“As the wave crashed down, the surfer fell.” “While Bob ate all the food, Rhonda looked on in
horror.”
If the relevant clause comes second, you do not need a comma:
“The surfer fell as the wave crashed down.” “Rhonda looked on in horror while Bob ate all the
food.”
5. In real prose stylistics, though, the Signal Word thing can get a little tricky. If you look at the
last sentence of item (3) above, you’ll notice that there is no comma between “and” and
“because” in the compound “…you don’t need both the comma and the and because the second
clause isn’t independent.” This is because of the basic rule outlined in (4). But because is a funny
word, and sometimes you’ll need a comma before its appearance in the second clause in order to
keep your sentence from giving the wrong impression. Example: Say Bob’s been murdered; the
question is whether Rhonda did it. Look at the following two sentences:
a. “Rhonda didn’t do it because she loved him.”
b. “Rhonda didn’t do it, because she loved him.”
Sentence a, which is grammatically standard, here really says that Rhonda did kill Bob but that
her reason for the murder wasn’t love, i.e., that the reason Rhonda killed Bob was not her love for
him. Sentence b says that Rhonda did not kill Bob and that the reason she didn’t is that she loves
him. In 99% of cases, what someone’ll be meaning to say is what b says. So, though nonstandard
in the abstract, b can be semantically
correct, correct in a meaning-based context.