Writing clear, straightforward, and grammatically correct English can be challenging. English words can be used as verbs or nouns, and sentences can be structured in a variety of ways. This flexibility can sometimes result in communications that are vague and confusing.

For non-native speakers of English, the use of articles and prepositions can be particularly difficult. And for all writers, whether they are in administrative or technical positions, the large number of synonyms and homonyms can be an obstacle to creating communications that achieve a desired result. This site provides examples of common grammatical errors and suggests possibilities for their correction.

Voice refers to the relationship between subject and verb. The subject tells us what the sentence is about and the verb indicates the action or state of being.

In the active voice, the subject performs the action indicated by the verb. Having the verb follow the subject is the preferred construction for sentences because it adds energy to the writing and establishes responsibility. In passive voice, the subject receives the action identified by the verb. This may be an appropriate style for some types of scientific or policy writing.

An adjective is a word that modifies a noun. It describes or tells us something about the noun, like what kind or how many. Sometimes an adjective is placed next to the noun it modifies, either directly before the noun (an ancient sword, the second notebook) or directly after (an image distorted, his dreams destroyed). Other times an adjective is separated from the noun it modifies, as in "the game was exciting. In these cases, a linking verb (such as is, was, or seemed) connects the noun and its modifier.

When two or more adjectives (modifiers) appear before a noun, they should follow a certain order. Here is the usual order of adjectives in a series:

advice, advise
affect, effect
all ready, already
all together, altogether
brake, break
choose, chose
cite, sight, site

conscience, conscious
dominant, dominate
elicit, illicit
envelop, envelope
forth, fourth
loose, lose
presence, presents

principal, principle
rein, reign
right, rite, write
stationary, stationery
threw, through, thorough
who's, whose
your, you're

Nouns identify persons, places, or things. Making English nouns plural can be confusing. Some nouns refer to things that can be counted and made into plurals (a hundred dollars, six miles, three children). Other nouns refer to things that cannot easily be counted (excitement, wisdom, traveling, electricity); these "noncount" nouns usually have no plurals but can be quantified with expressions like a lot of, much, some, many.

Parallel sentence structure exists when two or more sentence elements of equal importance are similarly expressed. Parallel sentence elements are often used for listing ideas or making comparisons. Both the structure of the elements and the form of the words benefit a sentence's clarity and symmetry.

Run-on sentences result when two clauses that could stand on their own are joined by a comma. There are four possible ways to correct this depending on the intended meaning:

• Use a period to create two complete sentences
• Separate the clauses with a semi-colon
• Add a comma and a coordinating conjunction between the clauses (and, or, but, nor, or yet)
• Add a comma and a subordinating conjunction or relative pronoun to subordinate one of the clauses
         Subordinating conjunctions: while, although, because, if
         Relative pronouns: which, that, who

Synonyms are words that mean essentially the same thing: dreary/gloomy, fury/rage, and injure/damage. But because they each have unique connotations, they cannot always be substituted for each other. For example, injure is used in reference to humans and animals while damage would refer to an object. We wouldn't say: "I injured my computer." When in doubt, use a dictionary for the precise definition of a word.

Avoid redundancy and restating concrete words abstractly: