Comma • Use • before a coordinating conjunction linking main clauses • following introductory clauses and phrases • between items in a series • to set off incidental comments (appositives, nonrestrictive clauses) • when meaning is unclear without its use • when authority figures tell you to use one while you are writing for them
Don't use • a single comma between a subject and its verb • when a subordinate clause follows a main clause • before the first or after the last item in a series • between two words joined by a coordinating conjunction
Semicolon • Use • instead of a coordinating conjunction between main clauses • to separate main groups of items in a list already using commas • Don't use • too frequently in the same document • between parts of unequal grammatical rank
Colon • Use • to connect explanation, details, or a quotation to a main clause • Don't use • more than one in a sentence • directly after prepositions or verbs unless you knowingly choose to violate the normal usage rules
Dash • Use • to indicate a sudden change of tone or idea • to emphasize, clarify, or interject • Don't use • too often • a hyphen(-) for a dash; dash(--) = two consecutive hyphens or an em-dash
Parentheses • Use • to insert nonessential material • to indicate citation • to introduce acronyms, abbreviations, etc. • Don't use • if the material can be better incorporated another way
Brackets • Use • to interpolate in quotations • as parentheses inside parentheses
Ellipsis • Use • to indicate an omission • Don't use • to indicate that you're starting a sentence in the middle • to alter meaning in a quotation
Apostrophe • Use • to indicate possessive case for nouns and indefinite pronouns • to indicate omissions in contractions • to indicate plurals of odd words, acronyms, and numerals (opt.) • Don't use • to indicate possessive case for personal pronouns • to add an "s" for making standard words plural
Single Quotation Marks • Use • within double quotation marks or for unusual terms • Don't use • to pretend you're not really using a word you're using
Double Quotation Marks • Use • to enclose direct quotes • for minor (internal) titles • correctly with other marks: • place period and comma inside • place colon and semicolon outside • place question mark and exclamation point inside when they apply only to the quoted matter, and • outside when they apply to the whole sentence • Don't use • to pretend you're not really using a cliche you're using
Hyphens • Use * • to integrate words into a functional unit • when your keyboard lacks bullets to set off listed items
Prepositions connect nouns or pronouns to other words. • The phrases created by this linkage are called prepositional phrases, and they usually function as modifiers— adjectives or adverbs—adding detail to the sentence. • Tree frogs are colorful. • Tree frogs of the Colombian mountain ranges to the north of the country's capital near the border are colorful, with markings on their limbs, between their eyes, underneath their arms, and on their backs in hues of red, orange, green, purple, and black.
Prepositional phrases consist of a preposition, which can be a word or a phrase, and its object: • PrepositionsObjects • according to Aristotle • because of jellyfishes' sensitivity • since the beginning • with regard to ecological studies • with the exception of white whales • throughout the article
Lists of prepositions can be found in any grammar book : • above, • around, • across, • below, • between, • by, • over, • past, • since, • throughout, • concerning, • despite, • etc.
Technical writers tend to use prepositions frequently because they often need to communicate details: • describing specific features of animals, • analyzing the particular configurations of chemicals, • explaining the effects of procedures, and • the like. • However, overuse of prepositional phrases confuses, rather than clarifying, the writer's point. • The design of the apparatus with the tubing and the electrical wiring was useful for diagnosis of the transmission of electrical impulses in the nerve tested.
Revising to avoid overuse of prepositional phrases makes the ideas and information • more readable, • easier to understand, and • easier to retain. • Consider using the object of the preposition as an adjective or converting the idea into a subordinate clause.