P. Fieguth - Grammar Summary Page
Paul Fieguth
Dept. of Systems Design Engineering
Faculty of Engineering
University of Waterloo
Waterloo, Ontario
Canada N2L 3G1
Tel: (519) 888-4567 x84970
FAX: (519) 746-4791

Grammar & Style Suggestions and References

I read too many reports with poor grammar, structure, ideas etc., so I'm going to start compiling the advice which I find myself writing. If you're going to be writing a report / project / thesis for me, then you may find it useful to glance through the rest of this page.

The document is divided into four parts, which will be of varying relevance depending upon the relative strengths and weaknesses of your writing style:

  1. Punctuation
  2. Words
  3. Sentences and Paragraphs
  4. Whole Document Structure

Here follow three grammar references, from elsewhere on the Internet, which may be of use, although they vary in purpose and thoroughness:

  1. Condensed grammar description.
  2. The eight parts of speech.
  3. Guide to Grammar and Style


Apostrophes, Colons, Commas, and Semi-Colons ...


Many non-native English speakers, especially those used to a different alphabet (such as Arabic or Chinese), seem to use inconsistent spacing in their writing. Colons, semi-colons, commas, periods are never preceded by a space and always followed by one:

Hello! What shall we do today? Three ideas: study, read, or exercise.

Pairwise punctuation (quotes, brackets etc.) have opposite spacing arrangements at the two ends, thus

In a sentence, parentheses (like these) or brackets [like these] are surrounded by spaces.
There is no space before following punctutation (like this period).
Quotes work the same way: "Hello", not " Hello "

I am not aware of uniform agreement regarding punctutations and quotes. My personal feeling is that punctutation for a quoted word goes outside of the quotes

Then he said "hello", and I shouted "hi".

whereas punctuation for quoted phrases or sentences may be placed inside or outside. I have a preference for inside:

"Let's go to the library," he suggested.
Then he said "I would like to read your thesis."

The position of a question mark should be inside the quotation if the quotation asks the question, outside if the remainder of the sentence asks the question:

Did he say "I don't know"?
Then he said, "What would you like to do?"


Use the apostrophe correctly. The most common error is to confuse "its" with "it's":

"it's" ALWAYS means "it is": It's raining today.
"its" is a possessive: His car, her house, its colour.

Do not use the apostrophe to create plurals, a problem which occurs most frequently with acronyms. Reserve the apostrophe to indicate the possessive tense:

The PTA's meeting on ABCs went well.
NATO's F18s are expensive.


Sentences with mis-used colons are very irritating to read. It is very simple to do it right!

The part of the sentence preceding the colon must be a complete sentence!!! So the sentence ...

Our ideas are: idea 1, idea 2, and idea 3.

is wrong!! "Our ideas are." is not a complete sentence, nor is it a header (discussed below). The irony is that this would have been just fine without the colon:

Our ideas are idea 1, idea 2, and idea 3.

If you wish to use a colon to introduce a list, make sure that it ends a complete sentence, then followed by one or more clarifiers:

We have three ideas: idea 1, idea 2, and idea 3.
We have the following ideas: ...
Our report is very interesting: reason 1, reason 2 ...

Note that what follows a colon does not need to be a list. The purpose of a colon is to separate a complete sentence phrase from some related, clarifying remark(s):

I have a great idea: let's read a book on grammar.
My thesis contains a profound result: the solution to cold fusion.

There is some judgement required in constructing such sentences: Although grammatically not correct, the occasional use of colons following headers can be effective in giving emphasis. This is similar to writing in point form, and should be avoided in formal writing.

Three ideas: idea 1, idea 2, and idea3.

An overview of our algorithm: step 1, step 2, and step 3.

In each case, the header preceding the colon is a noun phrase; no verb is present.

In general, avoid colons unless you know how to use them. If you use one, do not leave the part of the sentence preceding the colon "hanging".

Commas and Semi-Colons:

Most students don't use semicolons, so they consequently don't get mis-used very much either. The rule is very simple: only put a semicolon where you could put a period. That is, a semicolon separates two grammatically complete sentences:

We will develop an algorithm; we'll also do other stuff.

The semicolon case be useful in reducing the number of very short sentences in a paragraph. The phrases connected by a semicolon are meant to be somewhat more related than those separated by a period, so a semicolon can be a useful tool, if used consistently, in helping a reader to understand degrees of relationship.

The use of the comma is more subtle and errors are frequent! If in doubt, leave the comma out; I see more bad commas than I do missing ones. You won't go wrong if you stick to the following:


Latin acronyms, articles, prepositions, if/whether, and plurals.

Latin Acronyms:

The short forms i.e., e.g., n.b. are very widely used, but often incorrectly.

They are latin acronyms, so the periods are required; furthermore they must be followed by a comma, since their English equivalents are phrases which would have to be followed with a comma in the same way. Finally, do NOT interchange i.e., e.g., and n.b. They do NOT mean the same thing!

AcronymLatin MeaningEnglish TranslationActual Meaning
i.e.,Id estThat isThat is, specifically, thus
e.g.,Exempli gratiaFor the sake of exampleFor example
n.b.,Note beneNote wellNote well
QEDQuod erat demonstrandumWhich was to be demonstratedEnd of proof

Note the differences in the following three sentences:

I need a new workstation; i.e., a fast, expensive toy.
I would like a new toy; e.g., a new computer.
I want a new computer; n.b., it had better be fast.


Although rarely a problem for native English speakers, foreign students very frequently have problems with these, and the problems are VERY GLARING to native speakers, so it is worth getting these right. There are two types of articles: definite (the, these, this etc.) and indefinite (a, an, some). The choice of article is well defined:


Sentences having a preposition at the end are wrong! Each of the following is abominable:

Who are you going with?
Where are you coming from?
That is the idea I came up with.
That's something I won't put up with.

EVERY preposition needs to be followed by an object phrase (either a direct one or an indirect one). Some people argue in favour of having prepositions at the end of sentences, because the alternatives sound awkward:

Whence are you coming?
That is the idea with which I came up.
That is something up with which I will not put. (credit to W. Churchill)

However such contortions are unnecessary. One can almost always construct a perfectly reasonable, grammatically correct sentence:

With whom are you going?
From where are you coming?
I came up with that idea.

If you find yourself putting prepositions at the end of sentences, at the very least get used to looking for alternatives.

If / Whether:

Far too many writers are ignorant of the use of "whether," substituting the word "if." "If" and "whether" represent very different forms of speech!

"If" always introduces a condition, making some part of the sentence subject to the condition introduced by "if":

If it is raining, we won't go outside.

"Whether" tests a condition, it doesn't introduce it:

Can you tell me whether it is raining outside?

Technically, the sentence

Can you tell me if it is raining outside?

is stupid. It says, if it is actually raining, then tell me something; if it isn't raining, then don't say anything. As a general rule it is hard to ask a question with "if"; you almost always want "whether".

Commonly Confused Words:

Principal A main thing, something significant, head of a school
The principal rule is this: be nice to other people.
Principle A philosophy, an idea
Try to live based on good principles, such as being nice to other people.
Assure To make sure of, giving a promise
I assure you that I have turned the lights off.
Ensure To make sure of
Ensure that the lights are turned off.
Insure To secure against loss of money
I insure my house and my car in case of damage.
Complement A good fit, a natural combination
Chocolate and milk are complementary: they taste great together.
Compliment Something free (ie, no cost), a nice statement
Thank you for the compliment; that was a very nice thing to say!
Effect Normally a noun: anything produced by some cause
The effect of your actions has been significant.
Affect Normally a verb: to act, to change, to cause an effect
Your actions will affect me significantly.


Get plurals right! To some people, Latin plurals (crocus - croci, arena - arenae) sound pretentious, whereas to others arbitrarily-anglicized plurals sound ignorant (datum - datums, quorum - quorums). In general, use your judgment; by and large I prefer Latin plurals. The rules for Latin pluralization are

the suffix *um pluralizes to *a, *a pluralizes to *ae, *us pluralizes to *i

The most common mistake occurs with "criteria", followed closely by "data" and "media":

One criterion, Two criteria.
One datum, Several data.
One medium, The television media.

Hence, the data are interesting, the media are biased. Do not treat "data" or "media" as singular! If the plural form bothers you, use one of many possible alternatives:

The dataset is ...
The results are ...
The collection of data is ...

Also frequently confused are sets and types. If you're referring to a set or a type of objects, even though there are many things in the set, there is only one set, so the singular case is required:

This group of people IS smart.
This bushel of apples IS heavy.
The apples in this bushel ARE red.
The set of points IS irrelevant.

Finally, comparatives are sometimes confused:
Comparator ... Applies to ... Example ...
Less, Lesser Continuous valuesI have less money than you.
Few, Fewer Integer values I have fewer dollars.
Great, GreaterContinuous valuesI have great strength.
Many, More Integer values I can lift more pounds.
Less Adjectives This light is less bright.
More Adjectives This book is more interesting.

Sentences and Paragraphs


This topic logically follows a discussion of colons, since most lists follow a colon. The main issue with lists is that all elements in the list need to be grammatically consistent (e.g., same verb tense or sentence structure).

Individual preferences will vary widely, and to the extent that a list is meant to look like point-form writing no grammar rules really apply. However in a formal document I would recommend the following rules for all lists:


It will be very difficult to summarize paragraph writing in a few points, since it is a fairly subtle and creative topic. However I'll list a few points for now:


It is amazing how many formal projects I get which have no introduction or where the writing is in point form. Basic ground rules:


Good figures are crucial to a good document. In general, my advice when writing is to determine all of your figures and tables first; these set the overall content and structure of the document. Once the figures are in place, the text follows easily.


It is naive to suppose that I can teach you anything substantial about writing style in a paragraph or two. Serious students should read a guide (e.g., Strunk and White). However, a few tips:

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