When you talk to people face-to-face, you can gauge their reactions to what you say. Often their responses guide your tone and your choice of words. When you write, you cannot see your readers. Instead, you must imagine yourself in their place, focusing on their responses when you revise.

Besides affecting how well you achieve your purpose as a writer, your language can affect how well you are regarded by others. When you accurately assess the tone, formality, and word choice expected in a situation, you use the power of language to enhance your position. When you misjudge, you may find that others judge you harshly. Your future employer, your teacher, your supervisor, or others with authority may or may not be aware of their power to set language expectations or of their own responses to your use of language. However, when they see you try to write and speak as they feel a situation requires, they will appreciate your effort to use language powerfully, adjusting it to your audience and situation.

Like a speaker, a writer may come across as friendly or aloof, furious or merely annoyed, playful or grimly serious. This attitude is the writer’s tone, and it strongly influences the audience’s response. A tone that seems right to a reader conveys concern for the reader’s reaction. For instance, readers might reject as inappropriate a humorous approach to cancer or AIDS that ignores their feelings about the disease. To convey your tone, use sentence length, level of language, and vocabulary. The key is to be aware of your readers and their expectations.

Considering the tone you want to convey helps you choose words that are neither too formal nor too informal. Formal language means the impersonal language of educated persons who consider topics seriously. Usually written, formal language is marked by relatively complex sentences and a large vocabulary. It doesn’t use contractions (such as doesn’t). In contrast, informal language more closely resembles ordinary conversation. It uses relatively short sentences and common words. It may include contractions, slang, and references to everyday objects and activities (cheeseburgers, T-shirts, CDs). The writer may use I and address the reader as you.

The right language for most college essays lies somewhere between formal and informal. If your topic and tone are serious (say, for a research project on terrorism), then your language may lean toward formality. If your topic is not weighty and your tone is light (say, for a humorous essay about giving your dog a bath), then your language may be informal.

Jargon is the term for the specialized vocabulary used by people in a certain field, such as music, carpentry, law, or sports. Nearly every academic, professional, and recreational field has its own jargon. To a specialist addressing other specialists, jargon is convenient and necessary. Without technical terms, after all, two surgeons could hardly discuss a patient’s anatomy. To an outsider, though, such terms may be incomprehensible. To communicate with readers without confusing them, avoid unnecessary jargon.

Jargon also can include ways of using words. Some politicians and bureaucrats like to make nouns into verbs by tacking on suffixes like -ize.

Although privatize implies merely “convert to private ownership,” usually its real meaning is “sell off” — as might occur were a national park to be auctioned to developers. Privatize thus also can be called a euphemism, a pleasant term that masks an underlying different meaning (see 16d).

Similarly, technology terms such as access, format, interface, database, and parameters are useful to explain technical processes. When thoughtlessly applied to nontechnical ideas, they can obscure meaning.

Avoid needless jargon by favoring a perfectly good old word over a trendy one. Also avoid the jargon of a special discipline — say, psychology or fly-fishing — unless you are writing for readers familiar with the field’s details and terms. For general readers, define any specialized terms.

Euphemisms are plain truths dressed attractively, sometimes hard facts stated gently. To say that someone passed away instead of died is a common euphemism — humane, perhaps, in breaking terrible news to an anxious family. In such language, an army that retreats makes a strategic withdrawal, a person who is underweight turns slim, and an acne cream treats not pimples but blemishes. Even if you aren’t prone to using euphemisms, note them when you read evidence from partisan sources and spokespersons.

Slang, when new, can be colorful (“She’s not playing with a full deck”), playful (“He’s wicked cute!”), and apt (ice for diamonds, a stiff for a corpse). Most slang, however, quickly seems as old and wrinkled as the Jazz Age’s twenty-three skidoo! Your best bet is to stick to words that are usual but exact.