voiceless consonants long elsewhere The number of diphthongs varies significantly between dialects. Sursilvan dialects contain eleven diphthongs and four triphthongs (, , , and ). Other dialects have different inventories; Putèr, for instance, lacks , , and as well as the triphthongs but has , which is missing in Sursilvan. A phenomenon known as "hardened diphthongs", in which the second vowel of a falling Diphthong is pronounced as , was once common in Putèr as well, but is nowadays limited to Surmiran: strousch 'barely > . Orthography Romansh is written in the Latin alphabet, and mostly follows a phonemic orthography, with a high correspondence between letters and sounds. The orthography varies slightly depending on the variety. The vowel inventories of the five regional written varieties differ widely (in particular in regards to diphthongs), and the pronunciation often differs depending on the dialect even within them. The orthography of Sutsilvan is particularly complex, allowing for different pronunciations of the vowels depending on the regional dialect, and is not treated in this table. Morphology The following description deals mainly with the Sursilvan dialect, which is the best-studied so far. The dialects Putèr and Vallader of the Engadine valley in particular diverge considerably from Sursilvan in many points. When possible, such differences are described. Nouns are not inflected for case in Romansh; the grammatical category is expressed through word order instead. As in most other Romance languages, Romansh nouns belong to two grammatical genders: masculine and feminine. A definite article (masc. il or igl before a vowel; fem. la) is distinguished from an indefinite article (masc. in, egn, en or ün, depending on the dialect; fem. ina, egna, ena or üna). The plural is usually formed by adding the suffix -s. In Sursilvan, masculine nouns are sometimes irregular, with the stem vowel alternating: il mir 'the wall' – ils mirs 'the walls'. la casa 'the house' – las casas 'the houses'. irregular: igl iev 'the egg' – ils ovs 'the eggs'. A particularity of Romansh is the so-called "collective plural" to refer to a mass of things as a whole: il crap 'the stone' – ils craps 'the stones'. collective: la crappa 'rock'. Adjectives are declined according to gender and number. Feminine forms are always regular, but the stem vowel sometimes alternates in the masculine forms: fem. bial (sg.) – biala (pl.) 'good' masc. bien (sg.) – buns (pl.) 'good'. Sursilvan also distinguishes