How a hook works in writing
You should begin your essays (but don't have to) with something eye-catching — something that grabs the attention of your readers and makes them interested in your writing. This sentence(s), which is called the hook, comes at the beginning of your introduction.
First, two examples (magazine cover hooks) from the world-known magazine Reader’s Digest:
And here’s an introduction to an essay with a nice hook:
In the US, the number of people losing their lives as a result of doctors’ mistakes is bigger than that of people killed by guns. Although this is not usually on the news, statistics reveal that authorities must take measures to lower hospital death tolls as much as they endeavor to battle crime. In this essay, I will suggest three ways to save patients’ lives.
[the green sentence is the hook]
And now five ways to write effective hooks:
1. A question
Asking your readers to think about the topic is a great way to get them ready to hear more.
Example: "Why is it that those who leave their countries to study abroad never return?"
2. Descriptive words
Creating a picture in the reader’s mind can make him or her feel connected to your writing. Use words that describe the scene you’re trying to create.
Example: “There was absolute silence in the area after Nepal’s devastating earthquake."
3. Quotes of famous people
If you have nothing in mind to start with, quote something from a well-known figure — of course, it has to be relevant to the topic of your essay!
Example: “As Martin Luther King once said, 'There is power in unity and there is power in numbers'".
4. Some fact or definition
Such types of hooks for essays serve to surprise your reader. Give the interesting fact about something you are going to describe and discuss in your essay’s body, and you will grab the attention of your audience at once.
Example: "In the US, the number of people who lose their lives as a result of doctors’ mistakes is bigger than those killed by guns!"
Although I do not personally advise this in exams, this is still a fascinating way of initiating your essay. Remember that in the IELTS test, for example, you will have no access to the Internet or books to gather reliable statistics, so don't be too specific.
Example: "In every 18 minutes, four Americans die from the food that they eat.”