Relative Pronouns
7.2.2 Relative Pronouns
Who vs Whom.
Who is used as a subject and whom as an object. The examples below illustrate correct usage.
Give the award to whomever you prefer. [Objective case: whomever is the object of the verb prefer.]
Give the award to whoever will benefit most. [Subjective case: whoever is the subject of will benefit.]
Whom did you consult? [Objective case: whom is the object of consult.]
Who was the consultant on this case? [Subjective case: who is the subject of the sentence.]
He is one of the patients whom Dr Rundle is treating. [Objective case: whom is the object of is treating.]
He is one of the patients who are receiving the placebo. [Subjective case: who is the subject of are receiving.]
That vs Which.
Relative pronouns may be used in subordinate clauses to refer to previous nouns. The word that introduces a restrictive clause, one that is essential to the meaning of the noun it describes. The word which introduces a nonrestrictive clause, one that adds more information but is not essential to the meaning. Clauses that begin with which are preceded by commas. Two examples of correct usage follow.
A study on the impact of depression on US labor costs was published in the 2003 JAMA theme issue on depression, which contains articles on a range of similar topics. [Nonrestrictive; there was only one theme issue on depression in 2003.]
The issue of JAMA that contained the article on the impact of depression on US labor costs was the 2003 depression theme issue. [Restrictive; there are thousands of issues of JAMA.]
Following are examples of ambiguous or incorrect usage that highlight this grammatical problem.
Incorrect: |
The high prevalence of antibodies to the 3 Bartonella species, which were examined in the present study, indicates that health care workers should be alert to possible infection with any of these organisms when treating intravenous drug users. [There are more than 3 species of Bartonella. Hence, the correct form here would be “… the 3 Bartonella species that were examined.…”] |
Ambiguous: |
Many reports have been based on series of patients from urology practices that may not fully reflect the entire spectrum of illness. [Do the patients or the practices not fully reflect the entire spectrum of illness? Also, do the reports involve all or only some urology practices?] |
Reworded: |
Many reports have been based on patients in urology practices, which may not fully reflect the entire spectrum of illness. [Urology practices in general do not capture the range of the disease.] or Many reports have been based on data from urology practices that may not fully reflect the entire spectrum of illness. [Some particular urology practices do not capture the range of the disease, but others might.] |
Avoid: |
This morning he revealed evidence that calls the study’s integrity into question has been verified. |
Better: |
This morning he revealed that evidence that calls the study’s integrity into question has been verified. |
The addition of that after revealed frees the reader from backtracking to uncover the meaning of the sentence above. The use of that to introduce a clause is particularly helpful when the second verb appears long after the first has been introduced (above, the interval between revealed and has been verified).