Most Khmer vowel sounds are written using dependent, or diacritical, vowel symbols, known in Khmer as ' or ' ("connecting vowel"). These can only be written in combination with a consonant (or consonant cluster). The vowel is pronounced after the consonant (or cluster), even though some of the symbols have graphical elements which appear above, below or to the left of the consonant character. Most of the vowel symbols have two possible pronunciations, depending on the inherent vowel of the consonant to which it is added. Their pronunciations may also be different in weak syllables, and when they are shortened (e.g. by means of a diacritic). Absence of a dependent vowel (or diacritic) often implies that a syllable-initial consonant is followed by the sound of its inherent vowel.