Complete an analogy based on function or purpose.

People have been using analogies (comparisons that show how two pairs of things are related in the same way) for thousands of years. Ancient Greek philosophers like Aristotle used analogies to explain complicated ideas by comparing them to simpler, everyday things. Over time, teachers realized that analogies are a great way to test how well students understand the relationships between words.

So why do standardized tests love analogies? Because they show whether you can figure out how words connect, not just what they mean. One of the most common connections is function or purpose — what something is used for or designed to do. That is exactly what this lesson will teach you.

Before you can solve a function analogy, you need to understand a few key ideas. A function analogy pairs an object with the job it does, or pairs a person with the tool they use. Let's break that down into four core principles.

A picture can make the pattern much easier to see. The diagram below shows how a function analogy works. Notice that the relationship arrow between the first pair is exactly the same type as the arrow between the second pair. Both arrows say "is used for."

Notice the dashed lines on the left and right sides of the diagram. They remind you that the words in the same position play the same role. BROOM and SHOVEL are both tools. SWEEPING and DIGGING are both actions those tools perform. Keeping positions consistent is one of the biggest keys to getting these questions right.

There is no formula with numbers here, but there is a clear, repeatable method you can follow every single time. Think of it as your personal "analogy algorithm" — a set of steps that always leads you to the right answer.

The 4-Step Method

1. Step 1 — Read the stem pair. Look at the two words before the double colon (::). For example, SCISSORS : CUTTING.
2. Step 2 — Build a bridge sentence. Create a short sentence that links them: "SCISSORS are used for CUTTING." This is the relationship you need to match.
3. Step 3 — Test each answer choice. Plug the answer pair into the same sentence: "A _____ is used for _____." Only the correct answer will fit perfectly.
4. Step 4 — Eliminate and confirm. Cross out any answer where the sentence sounds wrong or where the relationship type is different (like a synonym pair or a part-to-whole pair).

Let's see the method in action with a quick example. Suppose the question reads: THERMOMETER : TEMPERATURE :: CLOCK : _____. Your bridge sentence is: "A THERMOMETER is the tool used to measure TEMPERATURE." Now test the blank: "A CLOCK is the tool used to measure _____." The answer is TIME.

Not every function analogy looks exactly the same. The SSAT mixes things up by presenting the relationship in different orders and with different types of words. The diagram below shows five common sub-types you will run into.

When you sit down with a question, quickly decide which sub-type you are looking at. This helps you build a sharper bridge sentence. For instance, if you see a person paired with an object, try the sentence "A _____ uses a _____ to do their job." If you see an object paired with an abstract idea, try "A _____ provides _____."

Let's solve an SSAT-style analogy from start to finish using the 4-step method.

The SSAT loves to include answer choices that look tempting but actually represent a different kind of relationship. Here are the most common traps students fall into — and how to dodge them.

The SSAT tests several different analogy types. Knowing how function analogies compare to the others will help you quickly identify what type you are dealing with — and avoid mixing them up.

As you move into the Upper Level SSAT and eventually into high school vocabulary, the words in analogies will get harder. However, the strategy stays the same: identify the relationship type, build a bridge sentence, and test every answer choice. The harder the vocabulary, the more important these steps become.

Try these five problems on your own. Use the 4-step method for each one. After you choose your answer, read the explanation to see if your reasoning was correct.