Esperanto uses twenty-eight letters from the Roman alphabet, and is a phonetic language (each sound has a single letter and each letter represents a single sound). The letters Q, W, X, and Y are not used. Five of the letters have a circumflex on top of them (ĉ ĝ ĥ ĵ ŝ) and one has a breve (ŭ). Esperanto speakers represent these letters in situations where the circumflex cannot be used (e.g. unformatted e-mail where only basic ASCII characters can be used) either by placing an "x" after the letter; placing an "h" after the letter (this is the method approved by Esperanto's creator, Dr. Zamenhof); or placing the circumflex itself (^) after the letter. On the Internet, most Esperantists use the "x" method.
Words are always pronounced with the accent on the penultimate (next-to-last) syllable.