Esperanto alphabet
Some people say that use of the diacritics (the letters ĉ, ĝ, ĥ, ĵ, ŝ, ŭ) makes the language less natural than it would be using only the basic letters of Latin alphabet. The letters ĉ, ĝ,  ĥ, ĵ  are not used in any other language in the world.