Ask a child what they find hardest on a verbal reasoning paper and a lot of them will say the same thing. Codes. The questions where a word turns into a string of letters or numbers and they have to work out the rule, then run it backwards or forwards. They look like puzzles from a spy film, and to a stressed ten-year-old in a timed exam, they can feel just as impossible.
They're not, though. Code questions follow a small number of patterns, and once your child knows them, the questions go from terrifying to almost satisfying. So let's pull them apart. What do they look like on a GL Assessment paper, why do clever kids drop marks, and how do you practise them at home without anyone crying?
What a code question looks like
The most common version gives you a word and its code, then asks you to crack a second word using the same rule. The rule is almost always about moving letters along the alphabet.
Here's a real-shaped example. The code for KEYS is ICWQ. Using the same pattern, what does FYLB stand for? Work it out. K to I is two letters back. E to C is two back. Y to W is two back. S to Q is two back. So the rule is "move each letter two places back to make the code." To go the other way and turn the code FYLB into a word, you move each letter two places forward. F becomes H. Y wraps round to A. L becomes N. B becomes D. The answer is HAND.
That wrapping round at the end of the alphabet is the bit that catches children. When Y needs to go forward two, it doesn't fall off the edge. It loops back to A. Z plus one is A. A minus one is Z. A child who hasn't met that idea will freeze the moment a letter near the end of the alphabet shows up.
Then there are number codes. Each letter in a word gets swapped for a number, usually based on its position in the alphabet or a code the question hands you. If you're told that in a certain code A is 1, B is 2, C is 3 and so on, then CAB comes out as 3, 1, 2. Some questions give a few worked examples and ask your child to spot the rule themselves. That's a step harder, because nobody's told them what the pattern is.
You'll also see letter sequences, where a string of letter-pairs follows a hidden rule, and letter-number codes that mix both ideas. The GL syllabus lists several code variants, and a single paper can use more than one. The good news is they all rest on the same two skills: knowing the alphabet cold, and being willing to check.
Why bright children lose marks on codes
The first reason is the alphabet itself. Sounds daft for a child sitting the 11+, doesn't it? But knowing the alphabet as a song and knowing it as a tool you can count along, forwards and backwards, from any starting letter, are two different things. Ask your child what comes three letters before P without singing from the start. If they hesitate, that's the gap. Under exam pressure that hesitation turns into a wrong count, and a wrong count turns a solvable question into a guess.
The second reason is the two-step trap. A code question often asks your child to do the rule in reverse from the direction it was shown. They see KEYS turning into ICWQ by going backwards, then they're handed a code and asked for the word, which means going forwards. Plenty of children work out the rule correctly and then apply it the wrong way round. Right thinking, wrong direction, no marks. It's one of the most common mistakes I've seen, and it's pure habit rather than ability.
Then there's the panic itself. Codes look harder than they are, so children who'd happily tackle a synonym question lock up when they see a row of capital letters. They skip the question, lose the marks, and worse, they lose the time and the confidence that would have helped them on the next one. A child who believes codes are impossible will make them impossible.
How to practise codes at home
Start with the alphabet, because everything else sits on top of it. Write the 26 letters in a line and number them one to twenty-six underneath. Pin it up. Get your child used to counting along it both ways, and to the idea that it loops, so after Z you're back at A. Once they can shift any letter forward or back by a given number without panicking, codes stop being scary. This single thing fixes more code marks than any clever technique.
When you move on to actual questions, make your child write the rule down in plain words before they touch the answer. "Each letter moves two back." Naming the rule out loud forces them to notice which direction it goes, and that's exactly where the two-step trap lives. A child who says the rule before applying it is far less likely to run it backwards by accident.
Build in a check at the end too. The neat thing about codes is that they check themselves. If your child decodes FYLB as HAND, they can re-encode HAND and see whether it comes back to FYLB. If it doesn't, they've gone the wrong way or miscounted, and they've caught it before the marker does. Teaching that loop-back check is worth more than any number of practice questions done without it.
And keep it playful where you can. Codes are genuinely the most game-like question on the whole paper, so use that. Write your child a secret message in a simple shift code and let them crack it over breakfast. Let them write one back and you decode it. My son got far more practice from leaving me coded notes around the house than he ever did from a worksheet, and he didn't notice he was revising. Why fight the format when it's already the closest thing to fun on the paper?
Knowing your child's exam board
One quick warning before you buy a stack of code workbooks. Code questions are strongly associated with GL Assessment verbal reasoning, which uses a fixed set of recognised question types. If your target schools use a GL-based test, codes will almost certainly appear. CEM-style and consortium papers handle reasoning differently and may not feature codes in the same way, or may bury them inside mixed sections.
So before you spend a penny, find out which board your schools actually use. A family in Kent preparing for the GL-based Kent Test will see codes. A family targeting a super-selective with its own bespoke paper might not. Match the practice to the real exam, not to whatever the nearest workbook happens to drill. Time spent on a question type your child will never sit is time stolen from one they will.
Frequently asked questions
What's the difference between letter codes and number codes?
Letter codes swap each letter for another letter, usually by shifting along the alphabet. Number codes swap each letter for a number, often its position in the alphabet or a value the question gives you. Both test the same underlying skill of spotting a rule and applying it consistently. Once your child is comfortable counting along the alphabet, both types use the same thinking.
My child knows the alphabet, so why do they still get codes wrong?
Usually it's direction. They work out the rule from the example, which goes one way, then apply it the wrong way to the answer. Get them to write the rule in words first and to check their answer by reversing it. That catches almost all of these mistakes, and it's a habit rather than a knowledge gap, so it fixes quickly.
Are codes harder than other verbal reasoning questions?
They look harder, which is part of the problem, but they're among the most predictable once your child knows the patterns. There are only a few rule types, and they repeat. A child who's met all of them and practises the alphabet count will often find codes more reliable than vocabulary questions. With a code, you can reason your way to the answer. With an unknown word, you can't.
How much code practice does my child need?
Enough that the patterns feel familiar and the alphabet count is automatic, not so much that they burn out. Short, regular sessions beat one long grind. A few questions mixed into wider verbal reasoning practice, plus the odd coded note for fun, will do more than an hour of nothing but codes. You're building familiarity, and familiarity comes from little and often.
Not sure which verbal reasoning question types your child is quietly losing marks on? ReadyFor11 gives you an honest, free benchmark with no paywall waiting at the end. Have a look at readyfor11.co.uk and see where your child actually stands. �������������������������������������������������������������������������������