Beyond the basic characters and their modifiers, kana writing uses a few small symbols that carry important information. The first is the sokuon, a small つ in hiragana or a small ッ in katakana placed before another character. The sokuon indicates a geminate consonant, meaning the following consonant is held briefly, producing a double sound. In a word like きっと ("certainly"), the small ッ represents a pause that doubles the "t" sound. The sokuon has no sound of its own; its role is purely to lengthen and emphasize the consonant that follows.
The second special mark is the chōonpu, written as a horizontal dash ー in katakana. It is used to extend the preceding vowel sound, marking the long vowels that appear in many loanwords. For example, コーヒー (coffee) is written コ + ー + ヒ + ー, where each ー prolongs the preceding vowel to produce "kōhī". Without the chōonpu, the word would be read as "kohi", which sounds quite different. The chōonpu has no counterpart in hiragana; long vowels in native Japanese words are written simply by adding another vowel character.
A third symbol is the nakaguro, a middle dot ・ used in katakana to separate foreign words or names that have been strung together. It is the katakana equivalent of a space, since Japanese normally runs words together without spaces. Furigana is another convention worth knowing: small kana, usually hiragana, are printed above or beside kanji to indicate the pronunciation. For example, the kanji 食べる is annotated with the furigana たべる to show its reading. These auxiliary marks and conventions turn the basic 46 characters into a complete and flexible writing system.