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Grammar and Punctuation

Filed on: October 22, 2007 | Written by | 6 comments

We often are approached with questions related to grammar. One reason for this entire English grammar curiosity lies in the ambiguity that is prevelant in the language. Here are some rather corful ones (especially for people in life/medical science related fields): 

I have observed that some authors insert a comma after e.g. and i.e. and some do not. What is correct?

Some journals use American English, while some use British English. In the American style of writing, a comma is inserted before and after i.e. and e.g. However, in the British style of writing, a comma is inserted before but not after these abbreviations.

In some research papers, I have seen that there is no comma before etc. When is a comma used before etc.?

A comma is used before etc. when it follows more than one listed item, for example, rivers, lakes, streams, etc. (comma used) but rivers etc. (no comma used).

Should a comma be used before "respectively," at the end of a sentence?

The usage of the comma before "respectively" at the end of a sentence is context specific. If the sentence is long and has many parameters, then use the comma for clarity. If not, the comma may be omitted. Thus, although it may appear as inconsistent usage of comma, it is not in fact an inconsistency issue. Furthermore, it is not a BrE/AmE issue.

Here are a few examples. Remember, these are merely guidelines; use your judgment to use this comma.

  • Drug X was administered to the rats and mice on experimental days 4 and 7 respectively.
  • Her first and second sons were named Mark and Anthony respectively.
  • The values of prostaglandin, EP-12, and catechin in the cholesterol-treated and control groups were 12.6, 4.8, and 3.2, respectively.
  • This third release mixes original compositions and classic covers, opening with the heavy salsa of "Llego La Orquestra" before harking back to Manhattan's Palladium Ballroom with "En El Tiempo Del Palladium" and reminding us of the classic sounds of Tipica 73 and Fania with "Se Formo La Rumba" and "Ahora Si," respectively.

Should the definite article "the" be used with taxonomic names of plants?

There do not appear to be stringent rules for inserting the definite article "the" before the taxonomic names of plants. However, the CBE (pg 423) states that for plants, the names at the rank of family and above are plural in form. Considering this, use of the generic "the" with such names appears to be appropriate.

Consider this sentence, "The Liliaceae are very diverse, and they have been separated in to numerous small families." Here, the sentence describes the family "Liliaceae." Therefore, the name of the family is preceded by the definite article "the."

Now, consider this sentence, "The molecular results show that the habit is not a homologous character in Cereeae." Cereeae is a tribe located in the family Cactaceae. Since the rank "tribe" is placed below "family," the name of the tribe is not preceded by the definite article "the."

Furthermore, taxonomic names at the rank of family and above may sometimes be inserted in parentheses. "Comparative anatomy of tribes Cereeae and Browningieae (Cactaceae)." In such constructions, for example, tribe name (family name) or species name (family name), the taxonomic name is not preceded by the definite article "the."

Note: Similar usage appears to be followed with the taxonomic names of animals, i.e., hierarchies at the level of family and above appear to be preceded by the definite article.

Update 1: We have recently released an ebook "10 Punctuation Rules Every Author Should Know" that can be purchased from the website.


[This is part of the "Grammar" series of posts, which covers everything and anything related to English language grammar.]

R4i card says:
On July 7th, 2011

The usage of the comma before "respectively" at the end of a sentence is context specific.
Thank you for posting.

Editage says:
On June 9th, 2010

@David: This is what The Canadian Style [A Guide to Writing and Editing] [URL: http://www.btb.termiumplus.gc.ca/tpv2guides/guides/tcdnstyl/index-eng.html?lang=eng], a reliable source for Canadian English usage, has to say on this issue:

"Some standard abbreviations such as i.e., AD, IQ, ESP, CBC and MP do not have to be spelled out because they are well known and in many cases occur as dictionary entries.

The abbreviations i.e. and e.g.—although these are identical in meaning to that is and for example—should be preceded by a comma, a dash or an opening parenthesis, but need not be followed by a comma."

You can find the above explanation here: http://www.btb.termiumplus.gc.ca/tcdnstyl-chap?lang=eng&lettr=chapsect7&...

David says:
On January 21st, 2010

You mentioned the American and the British conventions for using a comma after "i.e.". Do you know what is the Canadian convention?

Editage says:
On October 15th, 2009

@anju: It’s not incorrect. In fact, if you are using single, you should precede it with a. However, if you’re using a, you may or may not use single after it, depending on whether you want to emphasize the noun. For example, consider these two sentences: “A dot was detected” and “A single dot was detected.” They mean the same but the emphasis is on one dot in the second sentence.
@edo: Neither option is correct. The correct way to phrase it would be "Layers A and B were formed on the two main surfaces of substrate 10." The word "respectively" is used only to show the relationship between pairs of nouns. For example, if one wants to say that John has a blue car, and Jim a black one, then one could avoid the repetition of nouns by constructing the sentence thus: John and Jim have a blue and black car, respectively. Here, the use of "respectively" helps the reader to pair John with the blue car (because John and blue appear first in the order of names and cars), and Jim with the black car (because they appear second). In the example you cited, the word "respectively" is not required because there are no such pairs, nor is an order indicated.

edo says:
On September 24th, 2009

Here's one that has me stumped, regarding the use of "respectively."

Layer A is formed on one main surface of substrate 10.
Layer B is formed on the other main surface of substrate 10.

Can you say either of these:

Layers A and B were formed respectively on the main surfaces of substrate 10?
Layers A and B were formed on the main surfaces of substrate 10, respectively?

anju says:
On September 21st, 2009

Is it incorrect to use the article 'a' before the word single


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