General Writing and Grammar Help/HMI

Advertisement


Question
Dear Ted,

HMI stands for “Human Machine Interface”.
I can say: “There are two ‘Human Machine Interfaces’ in the table”, and that expression is correct.
Now, what about if I wanted to use the initials? Can I write: “There are two HMIs in the table”? I am asking because I have seen it written it this way as well: “There are two HMI’s in the table”. So, what is the correct form?
Also: “There is an HMI on the table” or “There is a HMI on the table”? I go for “There is an HMI on the table”, because its pronunciation sounds better. Which one of the two is correct?

Thank you,
Leonardo

Answer
Dear Leonardo:

HMI stands for “Human Machine Interface”.
I can say: “There are two ‘Human Machine Interfaces’ in the table”, and that expression is correct.
Now, what about if I wanted to use the initials? Can I write: “There are two HMIs in the table”? I am asking because I have seen it written it this way as well: “There are two HMI’s in the table”. So, what is the correct form?

*** This point is often argued.  MOST grammar books and style guides reject the use of an apostrophe in expressing the plural form.  For instance, the plural of CD is CDs.  There are some exceptions, which are given below.

*** Here is an entry from an English grammar forum.  It is based on the practices recommended by "The Oxford English Dictionary" --



   Apostrophes and plural forms

   The general rule is that you should not use an apostrophe to form the plurals of nouns, abbreviations, or dates made up of numbers: just add -s (or -es, if the noun in question forms its plural with - es). For example:

   ...
   MP MPs (e.g. Local MPs are divided on this issue.)

   1990 1990s (e.g. The situation was different in the 1990s.)

   It's very important to remember this grammatical rule.

   There are one or two cases in which it is acceptable to use an apostrophe to form a plural, purely for the sake of clarity:
   * you can use an apostrophe to show the plurals of single letters:
   I've dotted the i's and crossed the t's. Find all the p's in appear.
   * you can use an apostrophe to show the plurals of single numbers:
   Find all the number 7’s.

   These are the only cases in which it is generally considered acceptable to use an apostrophe to form plurals: remember that an apostrophe should never be used to form the plural of ordinary nouns, names, abbreviations, or numerical dates.


Also: “There is an HMI on the table” or “There is a HMI on the table”? I go for “There is an HMI on the table”, because its pronunciation sounds better. Which one of the two is correct?


*** Use AN.  Even though the statement is written and not spoken, you use the oral form in determining which article [a or an] to use.

Ted

General Writing and Grammar Help

All Answers


Answers by Expert:


Ask Experts

Volunteer


Ted Nesbitt

Expertise

I am the bibliographic instruction and reference librarian at a public college. Some members of the English department recommend me to their students. I offer assistance in grammar, punctuation, sentence structure, and paragraph development. My master`s thesis concerns William Faulkner`s tragic novels. I formerly taught advanced placement English at two schools in the Philadelphia area.

Experience

I have been one of the highest-ranked volunteers in this category for more than a decade.

Education/Credentials
B. A. and M. A in English; MSIS in Library & Information Sciences; graduate study in philosophy

©2016 About.com. All rights reserved.