Doubled consonants are geminated; the geminate fricatives /, and cannot be voiced. All plosives and fricatives in Muscogee can be geminated (lengthened). Voiceless stops are geminated and nasals also contrast in length. Consonants in a double parenthesis occur mostly as geminated versions of other consonants. While Japanese features consonant gemination, there are some limitations in what can be geminated. Thai, with its etymological spelling, preserves the implied pronunciation of these geminated consonant groupings. Doubled consonant letters can also be used to indicate a long or geminated consonant sound. True glottal stops normally occur only when they're geminated. It is trilled if geminated to and weakly trilled if preceded by or . Double (geminated) consonants were reduced to single ones. Like most Hungarian consonants, the sound can be geminated. All consonants except for /h/ can be geminated. All consonants except can be geminated ("doubled"). All the consonants, with the exception of the pharyngeal and glottal, can be geminated. Consonants, including and , can be geminated, often in words from Arabic.