Typing the six hatted letters

Every Esperanto course teaches ĉ on page one and leaves you to work out how to type it. The first answer you find, the US-International keyboard, gives you this:

• ^c ^g ^h ^j ^s - what US-International actually produces

Here is what works, per device, checked against the vendors' own documentation.

The six letters, and where they live

Esperanto has 28 letters, six of which English does not. Five wear a circumflex, the ĉapelo (hat), and one wears a breve. The alphabet page has the sounds; this is the plumbing.

All six are precomposed characters in Unicode's Latin Extended-A block: one character each, named the obvious way (U+0109 is latin small letter c with circumflex).

Each can also be built from two characters, a plain letter plus a combining accent. On screen the two look identical; to software they are not. Many search boxes and sorting routines handle only the single character properly. Everything below produces the single character.

The x-system is input, not spelling

Two substitute systems exist for a keyboard with no hats:

The x won because it is not an Esperanto letter, so cx can only mean ĉ and converts back mechanically. The h is a real letter: flughaveno (airport) has a real g then a real h, and no converter can tell that seam from a ĝ. That is why this site's URLs use x: /esperanto/words/sxi cannot be misread.

But neither is a spelling. The Akademio's 2007 position is that, where the hats cannot be used, the Fundamento's h-system comes first, and any other substitute is a technical expedient for when it is impractical, not a change to the orthography:

• Ĉu vi venos? - Will you come? (published)
• Cxu vi venos? - the same, typed with no hats: fine in a draft, not on the page

The Akademio's 2007 ruling on substitute letters (it names only the h-system) is in who decides what is correct Esperanto?, and why the h-system can mislead and the x-system cannot, in the ĥ question. To spell a word aloud, letter by letter, see letter names and spelling aloud.