Category Archives: Language


On Twitter I follow several accounts, one of which is Genius Brain Teasers.

One of the type of puzzles they publish is of the type: Remove x letters from this sequence to reveal a familiar English word.

My main criticism on this puzzle type is that they tend to be fairly easy. I’m a non native speaker, and if I can solve them, most native speakers should find them even easier. Nevertheless, as I don’t recall having seen them elsewhere, I think they deserve to be mentioned here.

Let me try to give you some examples:
Hidden word 1*/*****
Remove 5 letters to reveal a familiar English word:

Hidden word 2*/*****
Remove 5 letters to reveal a familiar English word:

Hidden word 3*/*****
Remove 5 letters to reveal a familiar English word:

Here’s a small variation of my own:
Hidden words 4*/*****
Remove 4 letters to reveal a familiar English word. Then, remove 4 other letters to reveal a different English word:

Hidden words 5*/*****
Again, you find the letters of 2 words. Remove 4 letters in 2 different ways to reveal 2 familiar English words.

You can check all your solutions here

New puzzles are published at least twice a month on Friday. Solutions are published after one or more weeks. You are welcome to remark on the difficulty level of the puzzles, discuss alternate solutions, and so on. Puzzles are rated on a scale of 1 to 5 stars.

Letterboggle (2)

In January 2014, I published a one puzzle blogpost on Letterboggle. Going through old notebooks, I discovered some more of these puzzles.

Let me restate the rules:
* All 26 letters of the alphabet have been used exactly once;
* two letters which are consecutive in the alphabet are always adjacent either horizontally, vertically or diagonally. Hence the alphabet forms a kind of snake throughout the firgure;
* The letter A does not need to be adjacent to the letter Z;
* A letter in the margin is present in the same row (if margin letter is adjacent to a row), in the same column (if the margin letter is on top or bottom of a column) or in the same diagonal (if the mnargin letter is in one of the corners);

Letterboggle (1)*
Letterboggle 2016-02-03 nr 1 exercise

Letterboggle (2)*
Letterboggle 2016-02-03 nr 2 exercise

Letterboggle (3)**
Letterboggle 2016-02-03 nr 3 exercise

Note that not all border fields contain a clue. This is on purpose.
Personally I would find alphabet snake a better name, but

You can check your solution here, here and here.

Christmas 2015 – a doublet

christmas treeCharles Lutwige Dodgson, alias Lewis Carroll, did not just write Alice in Wonderland, but also books on Mathematical subjects and puzzle books. The story goes that Queen Victoria, who reigned Britain during Charles live, was so enchanted by ‘Alice in Wonderland’, that she wrote the author and asked him to send her a copy of his next book. Charles dutifully did sent her his next book – on a mathematical subject.

Charles was also the inventor of a type of puzzle where one word has to be changed into another word by changing one letter at a time.
cot (replace ‘a’ with ‘o’)
cog (replace ‘t’ with ‘g’)
dog (replace ‘c’ with ‘d’)
Lewis Carroll says that he invented the game on Christmas day in 1877. The first mention of the game in Carroll’s diary was on March 12, 1878, which he originally called “Word-links”, and described as a two-player game. Carroll published a series of word ladder puzzles and solutions, which he called “Doublets”, in the magazine Vanity Fair, beginning with the March 29, 1879 issue. Later that year it was made into a book, published by Macmillan and Co.The one which Charles originally used was the problem to change HEAD into TAIL:
heal (Replace ‘d’ of ‘head’ to ‘l’)
teal (Replace ‘h’ of ‘heal’ to ‘t’)
tell (Replace ‘a’ of ‘teal’ to ‘l’)
tall (Replace ‘e’ of ‘tell’ to ‘l’)
TAIL (Replace ‘l’ of ‘tall’ to ‘i’)
The puzzles have been called Doublets, Word-links, Laddergrams, Word-golf, and Word-ladders.

At this time of the year, a Christmas puzzle seems appropriate. Over the past century, attention at Christmas seems to have shifted from Mary and her Baby to the christmas tree.

Try to change the word MARY into TREE in the fewest number of steps. Or, if you prefer that, you can change the word TREE back to MARY.

Marcel Danesi, Ph.D., on, believes that ‘solving them will give the verbal areas of the brain a veritable workout. The reason I believe this to be the case is that a solution entails knowledge of both word structure and semantics. The main semantic process involved is word association and, thus, recall, which is a powerful form of brain-activating thinking, at least as I read the relevant research. We are of course faced with the usual problem of trying to understand or explain how the research translates into benefits through puzzle-solving. The way I look at it is that puzzles such as the doublet can only be beneficial to overall brain health. As one’s semantic memory begins to wane through the aging process, giving the semantic parts of the brain a puzzle workout can only be advantageous

You can check your solution here

You are welcome to remark on the puzzle: its wording, style, level of difficulty. I love to read your solution times. Please do not spoil the fun for others by listing the solution. Solutions will be posted after one or more weeks.

Sources and further reading: The Levehsteind distance between two words is the number of operations that is needed to change one word into another by adding a letter, removing a letter or replacing a letter. The Damerau–Levenshtein distance is identical, but also allows the transpostion of two adjacent characters.
The distance between two words in a doublet as used by Dodgson is a special case of the Levenshtein distance: inseryion and deletion are not allowed, while all intermediate words must appear in a dictionairy. doublets as a complex network

Letter square

Conside the following square with letters.
Square alphabet

What number should go into the cell with the question mark?

Please try to solve the puzzles on your own. You are welcome to remark on the puzzles, and I love it when you comment variations, state wether they are too easy or too difficult, or simply your solution times. Please do not state the soultions – it spoils the fun for others. I usually make the solution available after one or two weeks through a link, which allows readers to check the solution without the temptation to scroll down a few lines before having a go at it themselves.

When you have solved this puzzle, you can check your solution here

You can find more puzzles like this one in our upcoming e-book on Logic Puzzles.


What’s special about the following sentence?

I am not very adept making awesome drawings.

As usual, you are welcome to report your solution times and comment on the solution, but please do not give away the answer – that may spoil the fun for others. I will publish the solution in one or two weeks after posting the puzzle.

You can check your solution here

Complete the alphabet (3)

1) Complete the alphabet*


In which row does the letter Z go?

If you solved it, we have the solution to 1

As always, please don’t publish your solutions. Solutions can be found after 1-2 weeks on the solution page for those who want to check their solutions, or for those who are really stuck.
But scrolling is much easier, and really spoils the fun for others.

You are welcome to post your solution times, make remarks, and discuss alternatives. Pointing out alternative solutions is also welcome, as they point out possible problems in the brain teasers.

Complete the alphabet (2)

1) Complete the alphabet*


In which row does the letter Z go?

If you solved it, we have the solution so you can check yours

One of the nice things of wordpress is its detailed visitor stats.
This blog had 6900 views in 2012.

The visitors have come from (in from most to fewer, only countries > 5 views represented:

United States India United Kingdom Netherlands Canada Australia
Ireland, Philippines Singapore Belgium Turkey Pakistan Germany Romania
Saudi Arabia France Spain Brazil Jordan Korea, Malaysia Hong Kong Greece
Poland Denmark New Zealand Italy Indonesia United Arab Emirates Norway
South Africa Sweden Taiwan Switzerland Mexico Algeria Israel Austria
Lebanon Finland Portugal Qatar Iceland Iraq Hungary Kuwait Jamaica
Ukraine Nigeria Russian Federation Egypt Serbia Bangladesh Japan
Thailand Belize Slovakia Viet Nam Nepal Argentina Latvia Kenya Estonia Armenia

There were 38 new posts, brining the total up to 52. 127 new pictures were uploaded.
The busiest day of the year was December 17th with 97 views.

The most popular posts date back to 2011, all types of river crossing puzzles.
Oh, and the most poopular page was the page with the solutions.