1. A computer-implemented method comprising: displaying, in a user interface, first objects displaying respective first characters, each first character being a consonant of a language script, wherein the first objects are arranged circumferentially to define an interior region in which no other objects displaying characters are displayed; receiving a single selection of one of the first objects that displays one of the first characters, wherein the single selection causes the displayed one of the first characters to be a selected first character; and in response to receiving the single selection, displaying, in the user interface within the interior region, and while continuing to display the first objects, other, second objects displaying respective other single characters of the language script, each other, single character being a combination of the consonant of the selected first character, and a dependent vowel marker that, according to a language rule, is valid for the consonant of the selected first character.