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Pick TwoActivity

Key word transformation: how to write one

B2–C1Updated Live examples

A key word transformation gives students a sentence, a word they must use unchanged, and a second sentence to complete so that it means the same. It is the most demanding task in the Cambridge papers because it tests grammar, vocabulary and collocation at once, and the most useful in class for exactly the same reason.

Also called

The same task goes by several names: sentence transformation, rewrite the sentence, use of english part 4, complete the second sentence. They all describe the exercise below, and this page uses key word transformation throughout.

What one item is made of

The lead sentence
The original meaning. Natural English, and unambiguous.
The key word
Given in capitals and used unchanged. Changing it is an automatic zero, so the constraint is the task.
The frame
The start and end of the second sentence, which fix everything except the part being tested.
The word limit
Usually between two and five words. Contractions count as two.

When to use it

Works well at B2–C1. Reach for it when:

  • You are preparing a class for B2 First or C1 Advanced, where this is Part 4.
  • You want to test one structure against a paraphrase: passive, reported speech, conditionals, comparatives.
  • You need to know whether a structure is genuinely available to them, not just recognisable.

Choose something else when:

  • The class is below B2. The instructions alone cost more than the practice returns.
  • You want fluency. This is the most analytical task in the set and it will not produce speech.

How to write a key word transformation exercise

  1. Step 1:

    Choose the structure first

    Decide what you are testing — the passive, reported speech, a conditional — and then find a sentence that hides it.

  2. Step 2:

    Write the lead, then the paraphrase

    Write both full sentences before you cut anything. If the two do not mean exactly the same, the item is unfair.

  3. Step 3:

    Pick a key word that forces the structure

    The word must make the target grammar the only route. If a student can answer without it, it is not doing its job.

  4. Step 4:

    Cut the frame so only the target is missing

    Everything either side is given. The gap should contain the structure and almost nothing else.

  5. Step 5:

    Count the words and list the alternatives

    Set the limit at the answer's length. Then write down every other answer that fits the limit and means the same — there is usually one.

Mistakes teachers make

  • Not thisKEY WORD: went — They ____ to the beach.

    BetterKEY WORD: TAKEN — We ____ to the beach by my uncle.

    If the key word can be dropped in without changing anything, the item tests copying.

  • Not thisLimit: 2-5 words. Answer: was not allowed to go (5 with contraction)

    BetterState plainly that contractions count as two words

    Students lose marks on the count rather than the grammar, which teaches nothing about English.

  • Not thisLead: He is a good cook. Key: WELL. Answer: cooks well

    BetterLead: He cooks better than anyone I know. Key: AS. Answer: as well as

    An item with two equally good answers cannot be marked. Tighten the frame until one answer remains.

Try it: key word transformation examples

Real items, not screenshots. Answers are checked in your browser and never sent to us, so you can share this page with a class exactly as it is.

Complete each second sentence so it means the same as the first, using the word in capitals. Do not change that word.

1Complete the second sentence using the word given. Use between two and five words.

  1. 1Someone stole my bicycle last night.

    STOLEN

    My bicyclelast night.Complete: My bicycle … last night.

    0 / max 5 words

  2. 2“I will call you tomorrow,” she said.

    WOULD

    She said that shethe next day.Complete: She said that she … the next day.

    0 / max 5 words

  3. 3I have never seen a better film.

    BEST

    This isI have ever seen.Complete: This is … I have ever seen.

    0 / max 5 words

  4. 4It is not necessary for you to come early.

    HAVE

    Youcome early.Complete: You … come early.

    0 / max 5 words

4 to go

Variations worth knowing

No key word
Give only the paraphrase frame. Easier, and a good stepping stone at strong B1.
Key word given, no frame
Students write the whole second sentence. Harder than the exam, and useful once the format is secure.
Find the mistake
Show a wrong answer and ask why it scores zero. Faster than doing another ten items, and it teaches the rules of the task.

Grammar topics that suit this task

Where it appears in the Cambridge levels

Pick Two Activity is independent and not affiliated with Cambridge University Press & Assessment. These pages describe the level you are teaching towards; always check the official site for the current format.

Exam practice in this format

Frequently asked questions

How many words are allowed in a key word transformation?

In the Cambridge papers, between two and five words including the key word, and contractions count as two. Set the same limit in class so the practice matches the paper.

Can students change the key word?

No, and that restriction is the task. A changed key word scores zero even when the sentence is perfect English, so it is worth saying out loud in every lesson.

What level should I start these at?

Strong B1 at the earliest, and normally B2. Below that the format costs more attention than the grammar it tests.

What if two answers are possible?

Rewrite the frame until only one fits, or list both as accepted. Items with two good answers are the most common flaw in teacher-written transformations.