Not to long ago (5/30/18), I happened to post the following Question of the Day on Facebook:

It wasn’t that long ago that putting food in liquid nitrogen was something you’d only see in a high school science class, but it’s also becoming a mainstay of modernist cooking. It’s odorless, tasteless, and harmless because it’s so cold (–320.44°F to be exact), it boils at room temperature and evaporates out of your food as it rapidly chills it.

A. NO CHANGE
B. tasteless, and harmless, and because
C. tasteless and harmless, because
D. tasteless, harmless and because,

Granted, it’s not the most straightforward question I’ve ever asked, but it’s also not the absolute trickiest. I was expecting people to get to the right answer pretty quickly.

In this case, though, the first two proposed answers were incorrect, and no one posted the correct one until it had been up for at least a few hours. I was a little taken aback, but then I realized that the question presented a very common stumbling block — one that I discovered I had never explicitly devoted a post to.

So here goes:

At the most basic level, the question is separating sentences/comma splice question. The phrase because it’s so cold initially appears to belong at the end of the first clause: It’s odorless, tasteless, and harmless because it’s so cold (–320.44°F to be exact).

The problem, however, is the sentences cannot be divided there without creating a comma splice — two complete sentences separated by only a comma.

Sentence 1: It’s odorless, tasteless, and harmless because it’s so cold (–320.44°F to be exact)

Sentence 2: It boils at room temperature and evaporates out of your food as it rapidly chills it.

The tip-off, in this case, in comma + it, which typically signals a comma splice.

(B) creates the same error, as well as some ambiguity about where the sentences are divided. The break can occur at the same place as in (A), or it can occur earlier:

Sentence 1: It’s odorless, tasteless, and harmless

Sentence 2: Because it’s so cold (–320.44°F to be exact), it boils at room temperature and evaporates out of your food as it rapidly chills it.

Either way, though, the two sentences are separated by only a comma and thus cannot be correct.

There are two principal reasons people get questions like this wrong:

The first is that they have trouble determining when a statement is and is not a sentence. They may not realize, for example, that a statement that begins with a pronoun (e.g., it) can be a sentence because it does not make sense out of context, or that a sentence can begin with because.

Aside from knowing that answers containing comma + pronoun typically signal a comma splice (which in turns requires quick recognition of pronouns), along with the fact that it is acceptable to begin a sentence with because, there is no easy workaround if the issue is a genuine sentence-identification problem.

Much of the time, however, students answer this type of question incorrectly because they neglect to do something very simple — that is, read all the way to the period.

Let me reiterate this: even if you think you know the answer to an ACT® English/SAT® Writing question — particularly one involving punctuation — make sure you read the entire sentence in which it appears before you mark your answer. A statement that seems fine on its own may create a serious problem when read in its full context. Moreover, the information necessary identify the right answer might not be included in the underlined portion.

Take another look at the sentence:

It’s odorless, tasteless, and harmless because it’s so cold (–320.44°F to be exact), it boils at room temperature and evaporates out of your food as it rapidly chills it.

In this case, comma splice appears in the non-underlined portion of the sentence. As a result, if you do not read the full sentence, you have no way of identifying the problem. Considered on its own, the beginning of the sentence seems perfectly acceptable.

Making things even more difficult, the close-parenthesis after exact forms a sort of visual boundary, distracting from the comma-splice “clue” (comma + it).

The correct answer, (B), is likely to strike you as wordy and awkward, and you may even eliminate it upfront. However, (B) is the only possible option. Why? Because comma + and = period. Consequently, it is the only option that eliminates the comma splice and separates the two sentences in a grammatically acceptable way.

Now, granted, when you’re in the middle of actually taking a test, it can be very easy to get distracted by shiny objects (like parentheses) and lose track of whether you’ve just read a full sentence.

So instead of thinking in terms of sentences, think in terms of simple punctuation: don’t stop reading until you hit the period.

Ok, got that? Period = stop; no period = don’t stop.

To keep yourself on track, write READ TO PERIOD (or just PERIOD) at the top of your test. It might seem like a tiny thing, but in my experience, stopping too early in a sentence is one of the most common reasons students lose points unnecessarily. Preventing it from happening is among the easiest ways to raise your score.