The word “doctor” is also used as a verb. The Merriam-Webster online dictionary says that one meaning of the verb “doctor” is to give medical treatment. For example, she doctored her sick friend. That makes sense. But personally, I have never heard the term used that way. In my opinion, it is more common to nurse someone back to health.

Sometimes people say “doctor” to mean “fix”. For example, he has doctored that clock several times. But again, this usage is rare.

A more common usage of the verb “doctor” is to transform something in an honest or dishonest way. For example, the school board official was accused of doctoring her study results. When we transform something, either in an honest or dishonest way, we sometimes add the word “up” to “doctor”. For example, the writer doctored up the script to better fit the actor. Here is a dishonest example: The legal team was accused of doctoring up photographs of evidence.

If something is exactly what you want, it is “just what the doctor ordered”. This expression can be used in many situations. For example, if I worked all week, a night on the couch with a good movie might be just what the doctor ordered.

Our last expression is this: Doctors make the worst patients. This means it is difficult to give people advice about something that they do for a living. This is because they might feel they know better than the person giving the advice. For example, Mary tried to persuade her boss at the bank to seek help for his growing debts. But he got angry. He said he knew best how to deal with his money. Mary just shook her head and said to herself, “It’s true. Doctors make the worst patients.”

Prefixes are important clues for you to determine an unknown word. Since pre- means “before”, the word “prefix” is literally “to fasten before”, that is, “to place or attach before”. 【小题1】A prefix consists of a letter or a group of letters placed before a root or word to change its meaning. For example, “disunion” means “separation”. The prefix dis-, meaning “opposite of”, changes the meaning of “union” from positive to negative.

The most common prefixes are divided according to their meanings into four groups: negative prefixes, amount prefixes, placement and direction prefixes, and degree and size prefixes.

Probably you know the meanings of these words: unafraid, unbelief, uncertain, undecided and uneducated, as they share the common prefix un-which means “not, opposite”. 【小题2】Prefixes like un- and mal- that serve to give a negative meaning to a word or to reverse and undo an action are called negative prefixes. In other words, a negative prefix makes the meaning of a word negative or opposite.

【小题3】Unlike prefixes, which are placed before a root or word and change its meaning, suffixes are added to the end of a root or word and less likely to change its meaning than to show its grammatical use within a sentence. They change nouns into verbs, verbs into nouns, nouns into adjectives and so on. Notice how adding different suffixes to a word changes the way it acts(but not its basic meaning)in the following sentences.

1. Jane’s motivation in doing well is to make money.

2. Money is a major motivator in Jane’s career.

3. Jane’s boss gave her a raise to motivate her to do an even better job.

In each of the above sentences the italicized word has the same basic meaning of “causing someone to do something”. 【小题4】

The common suffixes are generally classified into three groups: noun suffixes, verb suffixes, and adverb suffixes.

The full stop, which comes from Greek punctuation (标点符号), is usually used to express the end of a sentence but now it frightens young people when used in social media communication as a sign of anger.

According to experts, youngsters used to communicating electronically break up their thoughts by sending each one as a separate message, rather than using a full stop, which they use only to signal they are annoyed. Some have said the full stop is redundant when used in texting because the message is ended just by sending it. “If you send a text message without a full stop, it’s already obvious that you’ve concluded the message.”

Owen McArdle from Cambridge University told the newspaper: “I’m not sure I agree about emails. I guess it depends how formal they are. But full stops are very much the exception in youngsters’ instant messages, and have a new role in expressing anger.”

In 2015, a study from Binghamton University in New York suggested that people who finish messages with full stops are considered insincere. The study involved 126 undergraduates and the researchers found that text messages ending in the most final of punctuation marks-eg “lol.”, “let’s go to Nando’s.”-were considered being less sincere. Unusually, texts ending in an exclamation point-“lmao!”, “what body part even is that? I hope it’s your arm!” -are thought heartfelt.

Research leader Celia Klin said at the time: “When speaking, people easily convey social and emotional information with eye gaze, facial expressions, tone of voice, pauses and so on. People obviously can’t use these when they are texting. Thus, it makes sense that texters rely on what they have available to them-special signs, deliberate misspellings that imitate (模仿) speech sounds and, according to our data, punctuation.”