Slovenian uses diacritics or accent marks to denote what is called "dynamic accent" and tone. Standard Slovenian has two varieties, tonal and non-tonal.
Dynamic accent marks lexical stress in a word as well as vowel duration. Stress placement in Slovenian is predictable: any long vowel is automatically stressed, and in words with no long vowels, the stress falls to the final syllable. The only exception is schwa, which is always short, and can be stressed in non-final position. Some compounds, but not all, have multiple stress. In the Slovenian writing system, dynamic accent marks may be placed on all vowels, as well as r (which is never syllabic in Standard Slovenian, but is used for schwa + r sequences, when in consonantal environment); for example, vrt (garden) stressed as vŕt.
Dynamic accentuation uses three diacritic marks: the acute ( ´ ) (long and narrow), the circumflex ( ^ ) (long and wide) and the grave ( ` ) (short and wide).Tonal accentuation uses four: the acute ( ´ ) (long and high), the inverted breve ( ̑ ) or the circumflex ( ^ ) (long and low), the grave ( ` ) (short and high) and the double grave ( `` ) (short and low), marking the narrow ‘e’ or ‘o’ with the dot below ( ̣ ).