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Alphabet positions, memory aids, mirror letters and the patterns behind letter-series questions.
8 sub-topics, in the order to study them. Tap one to jump to it.
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A letter series follows the same logic as a number series, but the terms are letters. The one skill you need is converting letters to their positions in the alphabet (A = 1 to Z = 26) and then treating the problem like a number series.
In brief
Letter A B C D E F G H I J K L M Position 1 2 3 4 5 6 7 8 9 10 11 12 13 Letter N O P Q R S T U V W X Y Z Position 14 15 16 17 18 19 20 21 22 23 24 25 26
| Letter | A | B | C | D | E | F | G | H | I | J | K | L | M |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Position | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 |
| Letter | N | O | P | Q | R | S | T | U | V | W | X | Y | Z |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Position | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 |
In brief
Covers EJOTY, FKPUZ, ADGJMPSVY, Vowels A, E, I, O, U.
EJOTY = E 5, J 10, O 15, T 20, Y 25. These are the multiples of 5, so you can find any nearby letter in two steps (N is one before O, so N = 14).
FKPUZ = 6, 11, 16, 21, 26.
ADGJMPSVY = every third letter from A: positions 1, 4, 7, 10, 13, 16, 19, 22, 25.
Vowels A, E, I, O, U sit at positions 1, 5, 9, 15, 21.
The first half of the alphabet is A to M (1 to 13) and the second half is N to Z (14 to 26).
In brief
In the mirror alphabet A pairs with Z, B with Y, and so on.
In the mirror alphabet A pairs with Z, B with Y, and so on. The positions of every opposite pair add up to 27.
| A-Z | B-Y | C-X | D-W | E-V | F-U | G-T | H-S | I-R | J-Q | K-P | L-O | M-N |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1+26 | 2+25 | 3+24 | 4+23 | 5+22 | 6+21 | 7+20 | 8+19 | 9+18 | 10+17 | 11+16 | 12+15 | 13+14 |
Position formulas
Opposite of a letter at position p = 27 - p.
Position from the right end = 27 - position from the left end. So the 7th letter from the right is 27 - 7 = 20th from the left, which is T.
Wrap-around: after Z comes A again. If a calculation goes above 26, subtract 26; if it goes below 1, add 26. Example: X (24) + 5 = 29, minus 26 = 3 = C.
In brief
Pattern Example Next Logic Constant skip forward A, C, E, G I +2 each time Constant skip (+3) B, E, H, K N +3 Backward skip Z, X, V, T R -2 Increasing skip A, B, D, G, K P…
| Pattern | Example | Next | Logic |
|---|---|---|---|
| Constant skip forward | A, C, E, G | I | +2 each time |
| Constant skip (+3) | B, E, H, K | N | +3 |
| Backward skip | Z, X, V, T | R | -2 |
| Increasing skip | A, B, D, G, K | P | +1, +2, +3, +4, +5 |
| Opposite pairs | AZ, BY, CX, DW | EV | first letter +1, second letter -1 |
| Block shifts | ABD, EFH, IJL | MNP | each block moves forward 4 places |
| Alternate letters | ac, eg, ik | mo | each pair +4 |
| Forward then reversed pair | AB, DC, EF, HG | IJ | pairs alternate between forward and reversed order |
| Letter and number together | A1, C3, E5, G7 | I9 | letter +2, number +2 |
| Repeating block with gaps | _ b c a _ c a b _ a b c | a, b, c | the block abc repeats |
In brief
Covers Alphabetical rearrangement, Pairs with equal gaps, Letters between two letters.
Letter to the right or left of a given letter: convert to a number, add or subtract, then convert back. The 5th letter to the right of the 13th letter from the left is the 18th letter, R.
Alphabetical rearrangement: arrange the letters of the word alphabetically and count how many stay in the same place. For DREAM the alphabetical order is A, D, E, M, R, and only E keeps its position, so the answer is 1.
Pairs with equal gaps: for each pair of letters in a word, compare the gap in the word with the gap in the alphabet, which means list the pairs systematically instead of guessing.
Letters between two letters: the number of letters between positions p and q is |p - q| - 1.
In brief
Example 1.
Example 1. B, D, G, K, P, ?
Positions: 2, 4, 7, 11, 16. Differences: 2, 3, 4, 5, so the next difference is 6.
16 + 6 = 22, which is V.
Example 2. Find the opposite letter of K, then the letter 4 places after it.
K is 11, so its opposite is 27 - 11 = 16 = P.
Four places after P gives 20 = T.
Example 3. AB, CD, EF, GH, ?
In brief
Always write the position numbers under the letters before looking for a pattern. If there are two jumps alternating (for example +1, +3, +1, +3), treat them as one…
Always write the position numbers under the letters before looking for a pattern.
If there are two jumps alternating (for example +1, +3, +1, +3), treat them as one repeating cycle.
For long letter strings check whether the pattern repeats after a fixed number of letters (cyclic pattern) and fill the blanks by repetition.
For "opposite letter" questions use the pairs in 4.3; memorising the 13 pairs takes five minutes.
In brief
Forgetting wrap-around after Z. Using the number of letters between two letters as the position difference. The difference is one more than the number of letters between…
Forgetting wrap-around after Z.
Using the number of letters between two letters as the position difference. The difference is one more than the number of letters between them.
Mixing up counting from the left with counting from the right.
Practise with free MCQs and answer keys, then return here to fix what you got wrong.
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Last updated: . Notes are a revision aid; check official UGC sources for any rule or scheme that changes over time. Spotted a mistake? Write to netlawverse@gmail.com.