Editing Tip: 'Respectively' Revisited

Our post outlining the basic usage of the term respectively explains its common use with two parallel lists (i.e., two lists with the same number of items), as in the following example:

• The times until uptake of the modified antigen, the unmodified antigen, and the control antigen were 1 h, 2 h, and 5 h, respectively.

Lists involving prepositional phrases

However, the proper positioning of respectively may be less straightforward when a prepositional phrase is associated with the second list. For clarity, it is preferable to move respectively as close as possible to the end of the second list, before the prepositional phrase. For example,

• The times until uptake of the modified antigen, the unmodified antigen, and the control antigen were 1 h, 2 h, and 5 h, respectively, in a 37oC incubator.
• Not: The times until uptake of the modified antigen, the unmodified antigen, and the control antigen were 1 h, 2 h, and 5 h in a 37oC incubator, respectively.

Here, “in a 37oC incubator” is the prepositional phrase.

Alternative syntax

Note that on occasion, an author may write the following instead for stylistic reasons:

• The times until uptake of the modified antigen, the unmodified antigen, and the control antigen were respectively 1 h, 2 h, and 5 h in a 37oC incubator.

Again, respectively is as close as possible to the second list to clarify the relationship between the two lists. In this type of situation, when respectively precedes the second list, it is not surrounded by commas.

Multiple lists

Another issue is where to place respectively in the case of more than two parallel lists within a single sentence. In this case, to maximize clarity, respectively should again be placed before the second list. As an example,

• The times until uptake of the modified antigen, the unmodified antigen, and the control antigen were respectively 1 h, 2 h, and 5 h at 37oC and 1.5 h, 3 h, and 5 h at 40oC.
• Not: The times until uptake of the modified antigen, the unmodified antigen, and the control antigen were 1 h, 2 h, and 5 h at 37oC and 1.5 h, 3 h, and 5 h at 40oC, respectively.
• Not: The times until uptake of the modified antigen, the unmodified antigen, and the control antigen were 1 h, 2 h, and 5 h, respectively, at 37oC and 1.5 h, 3 h, and 5 h, respectively, at 40oC.

Here, one list (“the modified antigen, the unmodified antigen, and the control antigen”) parallels two lists (“1 h, 2 h, and 5 h” and “1.5 h, 3 h, 5 h”). The first sentence above clarifies this parallel, whereas the second may make it unclear to the reader which list is parallel to which. Meanwhile, the third sentence, with two instances of respectively, is cumbersome, potentially decreasing readability.

We hope that this tip will make using the term respectively easier as you write. As always, please email us with any questions or comments. AJE wishes you the best!