Use of the word "that" in formal tone, technical writing

Question

I need help settling a disagreement. I have read many posts about the word "that" — probably too many, since I have gotten myself confused! In this first example, there are two subordinate clauses, and I believe the first sentence (below) is correct. Which of these is preferable, and why?

Marine biologists at the University of Utah examined the louse genes and determined that their hosts split into three species 5–6 million years ago, and that these species were all equally abundant before whaling began in the 11th century.

vs:

Marine biologists at the University of Utah examined the louse genes and determined their hosts split into three species 5–6 million years ago, and these species were all equally abundant before whaling began in the 11th century.

Here's a different example in which I'm again of the opinion that the word "that" is necessary, but once again, I know not why:

During the winter months (July–October), southern right whales come so close to the shoreline that visitors can watch whales from strategically placed hotels.

vs:

During the winter months (July–October), southern right whales come so close to the shoreline, visitors can watch whales from strategically placed hotels.

I might also note that we are aiming for a formal (encyclopedic) tone. Any help would be appreciated. Thanks!

Answer 1

In both cases, that is the That-Complementizer, a marker for a tensed Noun Clause, or Complement.

In the first case, both that's are proper, since the repetition marks the two tensed complements that are conjoined by and, thus avoiding ambiguity, which is always a problem in a clause like this.

In the second case, the construction so Adj that S/such a NP that S uses the same complementizer that to mark the complement clause.

That complementizers can be deleted if they are obvious, as in sentences like

• She thinks (that) Mary likes him.
• I'm so tired (that) I can't sleep.

but not if they mark a subject complement and come first in a sentence

• That he arrived late is really his own fault.
• *He arrived late is really his own fault.

because the complementizer is needed as a flag to parse the clause.

However, the longer a sentence is, and the more grammatical complexities it has, the more it is usually not a good idea for a writer to delete every marker (article, preposition, pronoun, complementizer, etc.) that one can, just because it is possible.

Generally there is a function that these markers serve, to clarify a sentence, and one should always be aware that they're potentially there, whether one deletes them or not. Putting them back in is the first thing that a writer should do when a sentence is getting troublesome.

Answer 2

I think it is largely a matter of taste that you prefer the former.

That said, in formal writing especially, including that is advisable. It elucidates the fact that an entire phrase, rather than a single noun, is to be the subject of the preceding verb. This distinction is usually clear with or without that in informal English, and including it may even seem verbose; but in more technical English, with more complex sentences and relationships between phrases, its inclusion helps the reader scan the text. It's more precise.

In the examples you gave though, I can't see a strong preference for one or the other (other than stylistic preferences), as both forms are perfectly unambiguous.

Marine biologists at the University of Utah examined the louse genes and determined their hosts ...

The meaning is clear even at this point in the sentence, as their hosts would not be a noun subject of determined in this context.

During the winter months (July–October), southern right whales come so close to the shoreline, visitors ...

Again, the meaning is clear, because of so implies a subordinate phrase to follow. (So close? How close?)

Answer 3

First off, in your first example, you are using the word "that" as a conjunction. This means everything before and after that word is an independent clause or a complete sentence. In most cases, it's best to leave the word "that" for safety, but it is up to you to decide if you want to use it. I suggest you leave it.

Answer 4

Words which can be taken in two alternative ways such as "recognizing" in the above example, sometimes need the word "that" in order to prevent the reader from momentarily having to mentally halt to resolve the ambiguity. For instance, one can be recognized for his or her accomplishments or a fact can be recognized (its credence admitted) such as "this toll could tip..." If I were the writer in the above example, I would tend to include the "that" before "this toll" to avoid even the—admittedly—remote chance of the reader stumbling in that moment.