Which, that and who

Which, that and who should only refer to the noun that immediately proceeds them in order to avoid ambiguity. And it is important to keep the subject and the verb as close to each other as possible.

For example, the sentence below is ambiguous:

A survey of the quality of care of patients after surgery was compiled, as proposed by Said and Park (2019), who had suffered severe pain.

After initially reading this you may think that Said and Park had suffered severe pain rather than the surgery patients. This is because the subject, the surgery patients, was separated from the verb (had suffered) by the additional clause about Said and Park. Instead the sentence should be structured to keep the subject and the verb together, as below:

A survey of the quality of care of patients who had suffered severe pain after surgery was compiled, as proposed by Said and Park (2019).

An alternative option is to avoid using that, who or which. For example, the sentence below:

The recommendations for treating patients with an aneurysm, is reported in the new guidelines, which gives levels of certainty.

Could be rewritten as:

The recommendations for treating patients with an aneurysm is reported in the new guidelines. The guidelines give levels of certainty for treatments.

In this case, removing which and starting a new sentence that repeats the key word gives clarity to the sentence.

-ing form or that

Authors sometimes use the -ing form instead of using that, which or who. This is fine where it is not ambiguous.

For example:

Researchers that respond to the invitation to submit an article to the journal shall benefit from a speedy peer review.

Could be rewritten as:

Researchers responding to the invitation to submit an article to the journal shall benefit from a speedy peer review.

In this situation the -ing form appears directly after the noun so there is no confusion.

However, in the sentence below it is confusing whether it is the students or Doctor Park that has a good understanding of the subject.

Doctor Park taught the students having a good understanding of pediatric infectious diseases.

The author could clarify that it is the students that have a good understanding by writing:

Doctor Park taught the students that have a good understanding of pediatric infectious diseases.

However, if the author wants to write that it is Doctor Park that has the good understanding then this could be rewritten as:

Doctor Park, who has a good understanding of pediatric infectious diseases, taught the students.

Extract

The short extract below shows how authors have a tendency to use -ing over that, which and who.

Try taking the short quiz below to test your understanding. The examples in these questions are from real papers.