# Twins. Who are they?

You can find both in Istanbul, but none in water
They are the same size, but one of them is smaller

In some fields they can cause confusion
But if one grows, it will break the illusion

Different names, if called with the tone
But probably the same, if carved in stone

• – Matsmath Sep 23 '16 at 16:18

Is it

A capital i (I) and a lower case l (L)?

You can find both in Istanbul, but none in water

Both letters are in Istanbul, but neither in water

They are same size, but one of them is smaller

They are both full height, but the capital I is a bit smaller (Thanks @jwfrench !).

In some fields they can cause confusion

They look very similar in a lot of fonts

But if one grows, it will break illusion

If the lower case l is capitalized it no longer looks similar.

Different names, if called with the tone

Obviously called different and have different sounds

But probably same, if carved in the stone

A bit of a stretch here: because they look similar in text?

• I don't know who was faster because it shows same time(maybe you guys are twins?!). But your explanation of third line is better. – Traxo Sep 23 '16 at 16:22
• @Traxo My interpretation of the third line was actually what helped me to find the solution: there aren't many letters which appear in both "Istanbul" and "some fields". But I don't at all grudge PHP the tick: after all, I've got more than enough rep already ;-) – Rand al'Thor Sep 23 '16 at 16:33
• @randal'thor Actually I wasn't paying attention to word fields, now I see I should have :). I actually struggled to make that line less obvious but still keep rhyme! When you know solution, it's kinda hard to tell which line is most obvious, so thanks, I value your feedback. – Traxo Sep 23 '16 at 16:44
• Mostly correct! One of them being smaller refers to an uppercase [i] being slightly shorter than a lowercase [L] though, not thinner. And yes, the last part is not a stretch – it refers again to them being visually similar in contrast to their pronunciation (even though technically stone carvings of the letters would likely employ distinctions such as serifs...) – jwfrench Sep 23 '16 at 18:09
• These answers are the twins in the riddle. XD – The Great Duck Nov 9 '16 at 17:08

I think they are

capital I and lower-case l: "twins" because I and l are almost identical.

You can find both in Istanbul, but none in water

Both appear is Istanbul, but neither in the word "water". (Actually, technically, in Turkish the capital I in Istanbul has a dot, İstanbul, so the two letters are distinguishable. You shouldn't have chosen a Turkish word as your example ;-) )

They are same size, but one of them is smaller

I and l look almost identical in many fonts, but one is lower-case and the other is upper-case, and they may differ slightly in size even when almost identical.

In some fields they can cause confusion

Both letters appear in the word "fields", and their similarity can certainly cause confusion.

But if one grows, it will break illusion

Turning the lower-case i in "illusion" into a capital would break the word by giving it an apparent triple l (or triple I).

Different names, if called with the tone

When pronouncing them aloud, I and l certainly sound very different ...

But probably same, if carved in the stone

... but they look pretty much the same in writing.

• Wow, I guess it comes down to who gets the explanation correct first – bg6471 Sep 23 '16 at 16:11
• @bg6471 I just managed to do it first, but the edit history doesn't show that because PHP shadow-edited but your comment prevented me from shadow-editing :-/ – Rand al'Thor Sep 23 '16 at 16:13
• I don't care, you can take credit if you really want it. I am just glad that I was able to get an answer on a puzzle here – PartyHatPanda Sep 23 '16 at 16:15
• I actually thought the last line was referring to how it would be read aloud as per the line above. If it's in stone, I'm guessing it's a reference to Roman numerals and they both would be pronounced as the ancient Roman word for "one" would be – bg6471 Sep 23 '16 at 16:22
• @MrPie I don't mind :-) Thank you very much, by the way! I just noticed today that you'd placed a bounty on this for me. – Rand al'Thor Jul 18 at 20:58