Key Principles:

1. Key Principles: • Readers prefer that the main characters are subjects and most of the verbs name the actions of the characters. •  Sentences are cohesive with one another when we see at the beginning of a second sentence information that appeared toward the end of the preceding sentence. • Passages are coherent when we see that the topics of each sentence in the passage constitute a relatively small set of related ideas. • Try to limit the use of passive voice. • Be concise: • -Delete words and phrases that: mean little or nothing; that repeat the meaning of other words; that are implied by other words. • -Replace a phrase with a word. • -Change negatives to affirmatives. • Avoid hedging & intensifying; limit abbreviations

2. Common Usage Problems That/Which: Use “that” for restrictive or defining clauses that are essential to the rest of the sentence (a restrictive clause limits the possible meaning of the preceding subject). NO COMMA Use “which” for nondefining or nonrestrictive clauses that are not essential to the rest of the sentence (non restrictive clauses tell you about, but do not limit the meaning of a preceding subject). Can be omitted without changing the meaning. COMMA We will select the option that has the highest thermal efficiency. We will select Option A, which has the highest thermal efficiency. CetB mutants, which are tolerant to colicin E2, also have an altered… (all CetB mutants are tolerant) CetB mutants that are tolerant to colicin E2 also have an altered… (only some CetB mutants are tolerant)

3. , , , , , , That or which? The sequence _______ has had the most impact is the human genome. The NIH _______ has funded most of these studies has been pleased with the outcome. The universities ______ did most of the work included MIT/Whitehead. The Whitehead Center _______ was led by Eric Lander contributed about 1/3. DNA sequencers _______ were purchased at huge cost were essential to the effort.

4. Affect/Effect: Affect is almost always a verb; it means “to influence; to have an effect on.” Effect is primarily a noun meaning “result” or “consequence.” To affect something is to have an effect on it. But as a verb, effect means “to bring about; produce” (used in phrases like: “to effect change”). Continuous/Continual: “Continual” means repeatedly and “continuous” means without interruption. For two weeks, the whales continually dived to great depths in search of food. The spectrum of light is continuous. Criterion (singular)/Criteria (plural): The criteria for publication may include the significance of the results and the relevance to a broad community of scientists, but the central criterion should be the clarity of the writing. Antiserum (singular)/Antisera (plural): We generated an antiserum against tyrosine hydroxylase to… Antisera against dopa decarboxylase and tyrosine hydroxylase were used to… Datum (singular)/Data (plural): Datum is rarely used any more and data is now acceptable as either singular or plural. However, there are conservatives that don’t agree with this. If you need a singular form and don’t wish to use datum, write: “a data point.”

5. Assure/Ensure/Insure: A person assures (makes promises to, convinces) other persons and ensures (makes certain) that things occur or that events take place. Insure should be restricted to financial contexts. Complementary/Complimentary: Complementary is used for items that complete something (e.g., complementary strands of DNA). Complimentary is used for expressing civility, regard or praise, or given free (e.g., complimentary remarks, complimentary tickets, etc.) Principal/Principle: Principal (chief, primary, most important) is usually an adjective and principle (truth, rule, doctrine, course of action) is virtually always a noun. Quantify/Quantitate: Both are used as verbs, but quantify appears to be the preferred choice: -“quantitate is a needless variant of quantify, newly popular with social scientists, whose word choice should never be treated as a strong recommendation” (Bryan A. Garner in The Oxford Dictionary of American Style and Usage) -Quantify is recognized by 5 online libraries, but quantitate by only two. -Quantify is recognized by Microsoft products, but quantitate is not.  Use QUANTIFY in your writing.

6. Comprise/Compose: Correct use of these words is simple, but rare. The parts compose the whole; the whole comprises the parts. Comprise means “to contain” and compose means “to make up” (e.g., 52 cards compose a full pack; a full pack comprises 52 cards) Only: The precise placement of “only” in a sentence is important and dramatically alters the meaning of the sentence: Only I hit him in the eye yesterday. I only hit him in the eye yesterday. I hit only him in the eye yesterday. I hit him only in the eye yesterday. I hit him in the only eye yesterday. I hit him in the eye only yesterday. I hit him in the eye yesterday only.