The most common procedure by far is to add -o to every consonant:

a, bo, co, ĉo, do, e, fo, go, ĝo, ho, ĥo, i, jo, ĵo, ko, lo, mo, no, o, po, ro, so, ŝo, to, u, ŭo, vo, zo

These are the names given at the start of the Ekzercaro in the Fundamento de Esperanto. The non-Esperanto letters in the Latin alphabet are called: Q kuo, W duobla vo, X ikso, Y ipsilono.

Hence, the Esperanto word for ABC is aboco.

The system has the virtue of being easy to remember for adult learners, but it poses problems, especially in maths and science. For example, the name ro clashes with the Greek letter rho, the word do ("therefore") clashes with the letter do, and structural formulas in chemistry are hard to distinguish when read out. In 1949, F. J. Belinfante asked readers of Scienca Revuo whether they considered the system usable for all purposes; three-quarters of respondents said no. As a result there have been plenty of alternative proposals, but none are widely used yet. To give you an idea of what they look like, here are four of them.

The lexicographer Gaston Waringhien suggested adding -a to voiced consonants and -o to unvoiced (with some exceptions):

a, ba, co, ĉo, da, e, fo, ga, ĝa, ha, ĥo, i, jo, ĵa, ko, lo, mo, na, o, po, ra, so, ŝo, to, u, ŭo, va, za

The physicist Frederik Belinfante recommended the following for scientific work, based on 17 natural-language alphabets:

a, be, ce, de, e, ef, ge, haĉ, i, jot, ka, el, em, en, o, pe, ku, er, es, te, u, vi, ŭe, iks, ŭaj, zet Alternatives: ha, je, me, vaŭ, etc. For the Esperanto letters: ĉe, ĝo, ĥa, ĵe, ŝa, ŭo

The following alphabet-song was suggested by the poet Kálmán Kalocsay:

a, be, ce, de, e, ef, ge, ha, / i, je, ka, el, om, en, o, pa, / er, es, ta, u, ve, ĉa, ĝe, / ĥi kaj ĵi, eŝ, ŭo kaj ze, / plus ku, ikso, ipsilono, / jen la abece-kolono.

A very recent one, used by an accessibility add-on for Firefox, avoids clashing with any actual Esperanto words: