In research writing, we often have to write sentences that include lots of information and complex terminology. This can make our sentences harder to understand. To help our reader along, we can keep words that work together as close together as possible. This helps because these words often rely on each other for their meaning. If they are close together, the reader understands the meaning immediately. If they are further apart, the reader has to keep one of the words in mind until they get to the second, which can distract them from taking in the intervening information. This makes life harder for our reader. But how can you tell which words belong together? Here I describe some common words that should stay together in your sentences.

Once the reader learns who or what the subject is in a sentence, they immediately want to know what that subject is doing. If the subject and verb are not close together, the reader is distracted, waiting for the verb to find out the meaning. Consider this example:

Further research into the disadvantages of unplanned hospital admissions for patients with palliative care needs is needed.

Here, the subject of the sentence (further research) is separated from the verb (is needed), which makes it harder for the reader to focus on the important information in between. Putting the subject and verb together helps with this:

Further research is needed into the disadvantages of unplanned hospital admissions for patients with palliative care needs.

Keeping the subject and verb close together also avoids subject-verb disagreement, which can alter the meaning of a sentence. Check out my earlier post for more information on subject-verb disagreement and how to avoid it.

Sentences making comparisons contain lots of information (group names, variables, values, statistics, etc.) and it is often difficult to decipher what is being compared. Putting the things that are being compared close together often helps with this. Let’s take a look at an example:

Postoperative recovery time was faster in patients who received paravertebral blocks during breast cancer surgery than in patients who underwent general anaesthesia.

There is nothing terribly wrong with this, but we can make things a little clearer by putting the things being compared (highlighted in bold) together:

Postoperative recovery time was faster in patients who received paravertebral blocks than in patients who underwent general anaesthesia during breast cancer surgery.

Keeping things that are being compared close together in a sentence can also help to avoid potential ambiguity. For example:

The survey showed that female surgeons were less satisfied with their career progression than male surgeons.

Here, we are comparing satisfaction between female surgeons and male surgeons. Putting these two together in the sentence improves clarity and avoids the possible misunderstanding that female surgeons are less satisfied with their career progression than they are with male surgeons!

The survey showed that female surgeons were less satisfied than male surgeons with their career progression.

Cause and effect relationships describe how one thing (the cause) brings about another (the effect) and are very common in research writing. A common mistake is keeping the cause and effect separate in a sentence. Let’s consider an example:

The trial found no effect of lifestyle interventions during pregnancy in women with overweight or obesity on gestational weight gain.

In this example, the cause (lifestyle interventions) is separated from the effect (gestational weight gain), which makes the sentence harder to follow. We can help the reader by putting the cause and effect close together:

The trial found no effect of lifestyle interventions on gestational weight gain in pregnant women with overweight or obesity.

This immediately makes the sentence much easier to understand.

Modifiers are words or phrases that give information about other words or phrases in the same sentence. Sentences are often easier to understand if the modifier is closer to the thing it is modifying. Consider the following example:

Mental health disorders are common among people living with chronic pain and can affect their pain prognosis negatively.

Tagging the adverb negatively to the end of this sentence may distract the reader as they try to figure out what negatively is related to. We can avoid this unnecessary distraction by putting the adverb right next to the verb it is modifying:

Mental health disorders are common among people living with chronic pain and can negatively affect their pain prognosis.

In some cases, separating the modifier from the thing it is modifying can change the meaning of the sentence. Adverbs and adjectives like only and almost are common culprits here. Consider the following examples; each sentence has a different meaning depending on the position of only:

Only neoadjuvant chemotherapy was prescribed in 243 (27.9%) patients (meaning: no other therapy was given to these 243 patients)

Neoadjuvant chemotherapy was only prescribed in 243 (27.9%) patients (meaning: the therapy was prescribed but not performed)

Neoadjuvant chemotherapy was performed in only 243 (27.9%) patients (meaning: only 243 patients received the therapy; this is a small number).

So make sure you place adjectives and adverbs right next to the noun or verb they are modifying to avoid introducing ambiguity to your sentences.

Values should be positioned carefully in the sentences of your Results section. A common problem in research writing is tagging values on to the end of a sentence rather than next to their description. For example:

Mechanical ventilation was required by 84% of patients (771/917) and 20% required acute renal replacement therapy (186/917).

Although you can argue that the 186/917 clearly refers to the 20%, it is better to make this absolutely clear by putting the two next to each other:

Mechanical ventilation was required by 84% of patients (771/917) and 20% (186/917) required acute renal replacement therapy.

This avoids potential confusion and keeps your reader happy.

Related words and phrases belong together in a sentence. If we separate them with intervening information, we can make our sentences harder to understand or even change the meaning completely. Following the tips outlined in this post will help you identify those words that truly belong together in your sentences.

Claire Bacon is a former research scientist with professional qualifications in copyediting and medical editing. She edits scientific research papers and teaches courses on scientific writing.