Words from unity

[Simon Myers]

What's the longest word you can make where, starting from a letter, every subsequent additional letter added to the end gives a valid word.
You naturally get the first letter for free.

For example:

N -> NO -> NOT -> NOTA -> NOTAM -> NOTAMS
and
S -> SI -> SIR -> SIRE -> SIREN -> SIRENS

I've so far been unable to find sequence longer than 6 letters, but is there anything better?

Additionally, what if instead you can add the new letter anywhere in the word? Such as:
S -> SI -> SIR -> SIRE -> SPIRE -> ASPIRE -> ASPIRED

[Jon Corby]

According to my ODE2r wordlist 7 is the max for 'adding a letter to the end' (I've got 34 of them)

And I have also found many 9s (the wordlist doesn't include anything longer than that) for 'adding a letter anywhere in the word' (I've got 20 of them). I can see at least one of these which can have another letter added to it, so 9 isn't the limit here.

I'll post them if you like, but I didn't want to ruin the puzzle outright with the first post, particularly as it was all done by mo-sheen and not my brain, which may not have been Simon's intention.

[Charlie Reams]

Good puzzle, but I'm surprised you haven't already written a script to solve it. Or maybe you did, and you're just teasing us. I can't think of anything better than you suggested off the top of my head.

[David Roe]

How about

P - PA - PAR - PARS - PARSE - PARSER - PARSERS

?

[Dinos Sfyris]

For the second criteria:

I
IN
SIN
SING
STING
STRING
STARING
STARTING
STARTLING

This one has been mentioned a few times on the show, both by DC guests and viewer e-mails (much like the hilarious "The Russians used a pencil..." gag)

[Simon Myers]

I'll post them if you like, but I didn't want to ruin the puzzle outright with the first post, particularly as it was all done by mo-sheen and not my brain, which may not have been Simon's intention.

Feel free. Use any method, by hook or by crook. Just don't kidnap refugees and force them to do the work for you.

Good puzzle, but I'm surprised you haven't already written a script to solve it. Or maybe you did, and you're just teasing us. I can't think of anything better than you suggested off the top of my head.

I am tempted to write something to generate the best words (In fact I already wrote something similar for Kirk to identify non-obvious 9s that can have a letter removed from the front/back like HAIRBANDS or UNDERSEAL.

Alas, exams this week and final year project work stifle my efforts to waste time on such whimsical tasks, however.

For the second criteria:

I
IN
SIN
SING
STING
STRING
STARING
STARTING
STARTLING

This one has been mentioned a few times on the show, both by DC guests and viewer e-mails (much like the hilarious "The Russians used a pencil..." gag)

Ah, I did wonder when posting this if someone else had ever had the same idea. I wonder if this is the only nine.

Edit:
On the same lines then I suppose you can also have
I -> IN -> SIN -> SING -> STING -> STRING -> STARING -> STARLING -> STARTLING

[Jon Corby]

Ah, I did wonder when posting this if someone else had ever had the same idea. I wonder if this is the only nine.

As I said further up, there's 20 of them. And that's 20 unique nine letter words, I wouldn't count STARTLING twice with different roots.

[Simon Myers]

Ah, I did wonder when posting this if someone else had ever had the same idea. I wonder if this is the only nine.

As I said further up, there's 20 of them. And that's 20 unique nine letter words, I wouldn't count STARTLING twice with different roots.

Sorry, my reading comprehension suffers a bit under intense revision. I suppose give it a few days till more people have had an opportunity to see the thread and then post away. It doesn't prevent anyone from trying to finder longer (i.e. >9 letter) words later.

[Jon Corby]

Ah, I did wonder when posting this if someone else had ever had the same idea. I wonder if this is the only nine.

As I said further up, there's 20 of them. And that's 20 unique nine letter words, I wouldn't count STARTLING twice with different roots.

Sorry, my reading comprehension suffers a bit under intense revision. I suppose give it a few days till more people have had an opportunity to see the thread and then post away. It doesn't prevent anyone from trying to finder longer (i.e. >9 letter) words later.

Two words of the 20 can have a letter added to them to form the same 10 letter word, but I haven't really studied any of the others yet

[Martin Gardner]

We had the same discussion on the French Scrabble forum, apart from you can add a letter to the front or the back. Just going from the start to the end, but using conjugated verbs, you can do this:

RE
REA
REAL
REALE
REALES
REALESE
REALESER
REALESERA
REALESERAI
REALESERAIS (or -AIT)

If only I knew what it meant...