Ambiguity is a fascinating element of language, one an editor both struggles with and celebrates regularly. On the celebration side of things, ambiguity is an essential tool in the setup of a lot of short jokes, for one. As an example, an ambiguous statement leads to a misunderstanding, and in a VN said misunderstanding usually leads to an accidental love confession, resulting in the unfortunate victim stammering outrageously while blushing like a sunset. How cute. Ambiguity can also be a powerful tool in foreshadowing, since it allows a single statement to be interpreted in two ways, of which one can be applicable to the immediate present, thus making it a perfectly reasonable line to have in the present, and the other only meaningful when considering future events, usually causing the reader to look back and say, "Ahh-hah, now I see what it really meant." Ambiguity is also absolutely essential in writing clever blog post titles. But on the struggling side, ambiguity is often an enemy getting in the way of your reader enjoying your text.
As you read, your brain furiously analyzes words as they come in, building up and tearing down many possible syntactical structures for the sentence and many possible semantic interpretations of the various words and phrases, before eventually trimming this all down to a single interpretation of the sentence, typically over the course of a tiny fraction of a second. However, there are many stumbling blocks which can lengthen this process or thwart it entirely, notably including actual errors (misspellings, dropped words, incorrect grammar, etc.,), which is probably the chief reason why such errors are so frowned-upon in typical writing. Slowing down the reader's understanding, or preventing it entirely, is generally not the author's goal, assuming said author is not James Joyce.
Setting aside actual errors, ambiguity is one of the main impediments to a reader's understanding. Since one of a VN editor's chief goals is to ensure a script flows well for a reader, eliminating unintentional ambiguity is an important sub-goal. Even outside of intentional usage like in the cases mentioned in the first paragraph, ambiguity in English is still incredibly common, with small ambiguities cropping up constantly while reading essentially any text. Let's take a look at an example of a super-small ambiguity which slows down the reader just a tiny bit, a sentence containing my least favorite word:
I told you that I gave you the unburnt piece of toast, right?
Looks fine, right? As a whole the sentence is totally unambiguous. But while you're reading it, you're going to run into "that", and "that"'s a problem. "That" is an incredibly flexible word in the English language: it's a pronoun, a determiner, an adverb, and a relative pronoun. It's actually even more flexible in British English, where it can act as a subordinating conjunction, and even though most VN translations are written in American English, the lines there are pretty fuzzy, and it wouldn't be surprising or confusing to see a sentence like "He asked that she go" in a VN.
Now, in the sentence above, "that" is being used as a relative pronoun, but the prefix of this sentence, "I told you that" is also a perfectly well-formed English sentence in which it's instead being used as a pronoun, and if your brain follows such an interpretation immediately as you read the sentence, it'll take it a few extra milliseconds for your brain to unwedge itself, reorganize into treating "that" as a relative pronoun, and continue on forming the correct interpretation.
All right, doesn't sound like a big deal, does it? You're right. This particular, single instance isn't. But they add up, and you can do better, so you might as well. To put it in super technical jargon I didn't know until I was writing up this post, English has a so-called "zero relative pronoun" which can be used in place of relative pronouns like "that" which are introducing restrictive relative clauses. To give an example, since the previous jargon is so technical as to be basically useless, instead of the above sentence, you can just drop "that" and write:
I told you I gave you the unburnt piece of toast, right?
Now, look, I'm not saying this makes a huge difference, but doesn't this version feel a tiny bit better when you read it? Eliminating usage of overly-flexible words like "that" is a good way to reduce some ambiguity, but keep in mind this is a single example of a specific case. It just happened to be the one which prompted this blog post. However, I assure you, if you start reading your work with a careful eye out for the clarity of each line, you'll find tons of small, unintentional ambiguities popping out at you which you want to correct. Training yourself to look for them and to clean them up is one part of helping your text flow better.
I guess that's that. I hope you got something out of that, and I ask that, if you have questions, comments, or problems regarding this or "that", you leave a note below to that effect.