1. Grammar Errors that Create Confusion for the Reader
Run-on sentences
Misplaced modifiers
Unclear pronoun reference
Faulty parallelism
Agreement

2. The most important aspect of grammar is understanding what a sentence is
Sentence: A sentence is group of words with a subject and a verb that expresses a complete thought.
Fragment: A fragment is a group of words that either is missing a subject or a verb or does not express a complete thought.
Run-on: A run-on is two or more independent clauses that are not joined properly. For instance, a common mistake is to have a comma between the clauses.

3. Which are sentences (S), fragments (F), or run-ons (RO)?
1 Rubidium has no major uses, however, it is more common in the earth than zinc, copper, or nickel.
2 Although carbon dioxide occurs naturally, man has dramatically increased its concentration this past century.
3 Several systems can detect plastic explosives. For example, thermal neutron activation systems, nitrogen sniffer systems, and enhanced x-ray systems. RO S
S / F

4. Sentence (S), fragments (F), or run-on (RO)?
1 Rubidium has no major uses, however, it is more common in the earth than zinc, copper, or nickel. RO
Rubidium has no major uses; however, it is more common in the earth than zinc, copper, or nickel.
Rubidium has no major uses. It is more common in the earth than zinc, copper, or nickel.

5. Three situations in which run-on sentences are apt to happen
A pronoun in the second clause refers to a noun in the first clause.
The President’s popularity has plummeted, she apparently underestimated the opposition.
The President’s popularity has plummeted. She apparently underestimated the opposition.
Alternative corrections of first error.
The President’s popularity has plummeted; she apparently underestimated the opposition.

6. Three situations in which run-on sentences are apt to happen
2. A suggestion or directive occurs in the second clause.
You will be responsible for this material on the final exam, study it thoroughly.
You will be responsible for this material on the final exam. Study it thoroughly
Alternative corrections of first error.
You will be responsible for this material on the final exam; therefore, study it thoroughly.

7. Three situations in which run-on sentences are apt to happen
3. When two clauses are connected by a transitional expression.
Many people think protectionism can halt rising prices, however, the opposite is true.
Many people think protectionism can halt rising prices; however, the opposite is true.
Alternative corrections of first error.
Many people think protectionism can halt rising prices. However, the opposite is true.

8. Which are sentences (S), fragments (F), or run-ons (RO)?
3 Several systems can detect plastic explosives. For example, thermal neutron activation systems, nitrogen sniffer systems, and enhanced x-ray systems.
S / F
Several systems can detect plastic explosives. Examples include thermal neutron activation systems, nitrogen sniffer systems, and enhanced x-ray systems.
She spent her first week on the job as a researcher. Selecting and compiling technical information from journals.
S / F
She spent her first week on the job as a researcher, selecting and compiling technical information from journals.

9. Placing a modifier in its appropriate place is also important
These proteins indicate to the body what hormones should be given off among other things.
These proteins indicate to the body, among other things, what hormones should be given off.
Another common grammatical error is the misplacement of modifying phrases or words. Termed a misplace modifier or dangling modifier, this error commonly occurs with introductory participial and prepositional phrases. It also commonly occurs with the word “only.” In showing this slide, I cover up the revisions, and ask the students to identify where in the following sentences there are errors as far as placement of modifiers. A brief discussion can be found on pages in The Craft of Scientific Writing and pages in The Craft of Editing.
Moreover, an interactive web exercise on placement of modifiers (Grammar #2) can be found at the “Writing Exercises” link on the “Writing Guidelines for Engineering and Science Students” (
In meeting the staff of the Parks Department, the greatest problem was that of water leakage.
In meeting the staff of the Parks Department, we learned that the greatest problem was water leakage.

10. Unclear pronoun references cause ambiguities
Because the receiver presented the radiometer with a high flux environment, it was mounted in a silver-plated stainless steel container.
it???
If you receive an titled "Win A Holiday," do not open it. It will erase everything on your hard drive. Forward this out to as many people as you can. This is a very malicious virus and not many people know about it.
Another common grammatical error is ambiguous pronoun reference. This error commonly occurs with the pronouns “it,” “they,” and “this.” In showing this slide, I cover up the right column and ask the students to identify where in the following sentences there are ambiguous pronoun references. A discussion of pronoun references can be found on pages
Moreover, an interactive web exercise on ambiguous pronoun references (Grammar #2) can be found at the “Writing Exercises” link on the “Writing Guidelines for Engineering and Science Students” (
this???
This???

11. Making a list parallel also avoids confusion
Animals that come in contact with oil can develop rashes, sores, and may leave the area.
Animals that come in contact with oil can develop rashes, sores, and wandering tendencies.
Another common grammatical error is faulty parallelism. This error commonly occurs with lists. In showing this slide, I cover up the revisions and ask the students to identify where in the following sentence there is a parallelism error. A brief discussion can be found on pages and 259 of The Craft of Scientific Writing and page 123 of The Craft of Editing.
Moreover, an interactive web exercise on faulty parallelism (Grammar #2) can be found at the “Writing Exercises” link on the “Writing Guidelines for Engineering and Science Students” (
Animals that come in contact with oil can develop rashes and sores, and may leave the area.

12. Making a list parallel also avoids confusion
The new apprentice is enthusiastic, skilled, and you can depend on her.
The new apprentice is enthusiastic, skilled, and dependable.
Another common grammatical error is faulty parallelism. This error commonly occurs with lists. In showing this slide, I cover up the revisions and ask the students to identify where in the following sentence there is a parallelism error. A brief discussion can be found on pages and 259 of The Craft of Scientific Writing and page 123 of The Craft of Editing.
Moreover, an interactive web exercise on faulty parallelism (Grammar #2) can be found at the “Writing Exercises” link on the “Writing Guidelines for Engineering and Science Students” (
In his new job, he felt lonely and without a friend.
In his hew job, he felt lonely and friendless.

13. Subject-verb and pronoun-antecedent agreement are also important
Grammatical agreement involves:
number (singular or plural)
person (first, second, third)
case (nominative or objective)
gender (male, female, or neither)