Being aware of the subject of your sentence

Being careful with antecedents

Grammar has lots of crazy names for the different parts of an English sentence. I wasn’t lucky enough to learn all of these names and their meanings when I did my schooling, and thus when I hear people talk about grammatical errors my eyes often glaze over as I feel completely bamboozled! However, the more I read about grammar, the more I recognise that most of these terms are linked to very common mistakes.

A great example is the clumsy use of ‘antecedents.’ Essentially, an antecedent is the subject of the previous sentence. When writing in English we don’t want to have to mention the subject time and again in every sentence we are writing about it. Thus, after the topic sentence of a paragraph with a clear subject, you don’t need to mention it again, and the next sentence might start with: “Thiswas placed…”, because you have established what ‘this’ refers to.

In the following sentence, the flask is the antecedent, and it is referred to using the demonstrative pronoun “This…” in the second sentence, and the personal pronoun “It…” in the third sentence:

A large, metallic, thermally-insulated, vacuum flask was used to collect the residue. This was placed into an oven at 52 ºC for one hour. It was then removed and allowed to cool to room temperature. An additional steel ball of 33 g was used to aid melting.

But watch what happens when your advisor points out (in a comment) that the 33 g steel ball was actually added to the contents before the flask was placed in the oven. So you rearrange the sentence accordingly, but the antecedent (subject) changes as a result:

A large, metallic, thermally-insulated, vacuum flask was used to collect the residue. An additional steel ball of 33 g was used to aid melting. This was placed into an oven at 52 ºC for one hour. It was then removed and allowed to cool to room temperature.

You can see that the demonstrative pronoun “This…” in the third sentence is now referring to the ball, and not the flask. The reader is going to think that the ball was placed into the oven and then allowed to cool. This problem commonly comes about because sentences are moved without considering the way the antecedents were set up in the original text.

The other problem that I regularly come across is when the antecedent is ambiguous, as in the following:

The experiment ended with a combination of faeces and bones that were then separated by a centrifuge at 16 000 rpm. This was weighed on a balance and the mass recorded to the nearest 0.01 g.

In the above example, the antecedent is clearly the combination of faeces and bones but it is unclear whether the combined sample was weighed or if the mass of each was recorded separately. This ambiguity is often compounded in the following sentences, and ultimately means that they get lost when in the reading. When it is possible that there is an ambiguity, you must not use the demonstrative pronoun, but instead, restate the subject:

The experiment ended with a combination of faeces and bones that were then separated by a centrifuge at 16 000 rpm. The separated faecal matter was weighed on a balance, and the mass recorded to the nearest 0.01 g.

Problems with antecedents often come up when editing, or pruning text. Be aware of them as potential problems and look out for ambiguity when reading your own text. The combination of an antecedent followed by a demonstrative pronoun is a great way of making your writing concise, but be aware of their problems too.