11+ letter sequences: how to track two rules at once

To solve an 11+ letter-pair sequence, never read each pair as a two-letter word: split the sequence into two independent tracks — all the first letters on the top track and all the second letters on the bottom track — and work out each rule separately. Once the two tracks are separated, a confusing pair sequence turns into two straightforward alphabet-counting problems.

In 11+ Verbal Reasoning, letter sequences appear on almost every familiarisation and practice paper because they test working memory and systematic checking without relying on wide vocabulary ^[1] . Most questions print four or five pairs of letters (such as AZ, CX, EV, GT, ?) and ask for the next pair, though some leave the blank in the middle of the row so you can verify your rule on the pair that follows.

Step-by-step method

1. Draw top arches for the first letters and bottom arches for the second letters

On your rough paper or question booklet, draw small curved arrows above the sequence joining the first letter of every pair (A → C → E → G), and draw curved arrows below the sequence joining the second letter of every pair (Z → X → V → T).

Ignoring the second letters completely while you work on the top track prevents the most common mistake in this question family: trying to find a rule inside each pair (A to Z, C to X) instead of jumping from pair to pair.

2. Write the signed step size on every arch

Using a printed alphabet strip (A to Z), count the jump along each top arch and write the signed number (+1, +2, −3) directly on the arch. Look for one of the four standard 11+ sequence patterns:

• Constant step: +2, +2, +2 or −3, −3, −3.
• Arithmetic step (growing or shrinking by 1): +1, +2, +3, +4 or −4, −3, −2, −1.
• Alternating step: +2, +1, +2, +1 or +3, −1, +3, −1.
• Wrap-around step: a sequence moving forward past Z continues at A, B, C; a sequence moving backward past A continues at Z, Y, X.

Repeat the exact same count on the bottom arches for the second letters. The two tracks often move in opposite directions or use different step sizes.

3. Find the first letter, narrow the options, then find the second letter

Apply the top-track rule to write down the first letter of your answer, then apply the bottom-track rule to write down the second letter. If the blank is in the middle of the sequence rather than at the end, check one more jump after your answer to make sure it lands cleanly on the final printed pair.

Common traps and how to check

• Comparing letters inside the same pair: Looking for the gap between A and Z or C and X takes much longer and fails whenever the two tracks move at different speeds. Always jump from first letter to first letter and second letter to second letter.
• Forgetting to write + and − signs: Writing 2, 2, 2 without signs makes it easy to count forward on the final step when the track was actually moving backward (−2, −2, −2).
• Counting letters between instead of steps: A jump from A to C skips one letter (B), which is a step of +2, not +1. Whatever method your child uses on the alphabet strip, keep it consistent across every arch.
• Miscounting across the Z-to-A boundary: When a track nears Y, Z going forward or B, A going backward, jot down ... X Y Z A B C ... on the page so your child can point and count across the join without losing their place.

How to practise this question type at home

Give your child four or five letter-pair sequences and ask them to show the top arches and bottom arches with signed numbers written on every jump. Practising this neat visual layout for ten minutes does far more for accuracy than rushing through a long page of mental counts.

To try interactive Verbal Reasoning questions with full worked explanations, start a short practice session below.