Most letters in the Bulgarian alphabet stand for just one specific sound. Three letters stand for the single expression of combinations of sounds, namely ù (sht), þ (yu), and ÿ (ya). Two sounds do not correspond to separate letters, but are expressed as the combination of two letters, namely äæ (like j in Jack) and äç (dz). The letter ü is not pronounced, but it softens (palatalizes) any preceding consonant before the letter î.
There are three grammatical genders in Bulgarian: masculine, feminine and neuter. The gender of the noun can largely be determined according to its ending. The vast majority of Bulgarian nouns ending in a consonant (zero ending) are masculine (for example, ãðàä “city”). Feminine nouns include almost all nouns that have the endings –à/–ÿ (æåíà “woman”), a large group of nouns with zero ending expressing quality, degree or an abstraction, including all nouns ending on –îñò/–åñò (ïðåëåñò "loveliness"), and another, much smaller group of irregular nouns with zero ending which define tangible objects or concepts (âå÷åð “evening”). Nouns ending in –å, –î are almost exclusively neuter (äåòå “child”). The same regards a limited number of loan words ending in –è, –ó, and –þ (ìåíþ "menu"). The plural forms of the nouns do not express their gender clearly, although the ending –è is more likely to be used with a masculine or feminine noun (ôàêòè "facts"), while one in –à/–ÿ belongs more often to a neuter noun (åçåðà "lakes"). Also, plural ending –îâå occurs only in masculine nouns.
Two numbers are distinguished in Bulgarian - singular and plural. A variety of plural suffixes is used, and the choice between them is partly determined by their ending in singular, partly influenced by gender and partly impredictible due to the commonness of exceptions, irregular declension and alternative plural forms. Words ending in –à/–ÿ (which are usually feminine) generally have the plural ending –è, upon dropping of the singular ending. Of nouns ending in a consonant, the feminine ones also use –è, whereas the masculine ones usually have –è for polysyllables and –îâå for monosyllables (however, exceptions are especially common in this group). Nouns ending in –î/–å (most of which are neuter) use the suffixes –à, –ÿ (both of which require the dropping of the singular endings) and –òà.
With cardinal numbers and related words such as íÿêîëêî ("several"), masculine nouns use a separate count form in –à/–ÿ, which stems from the proto-Slavonic dual: äâàìà/òðèìà ó÷åíèêà (two/three students) versus òåçè ó÷åíèöè (these students); cf. feminine äâå/òðè/òåçè æåíè (two/three/these women) and neuter äâå/òðè/òåçè äåöà (two/three/these children). However, a recently developed language norm requires that count forms should only be used with masculine nouns that do not denote persons. Thus, äâàìà/òðèìà ó÷åíèöè is perceived as more correct than äâàìà/òðèìà ó÷åíèêà, while the distinction is retained in cases such as äâà/òðè ìîëèâà (two/three pencils) versus òåçè ìîëèâè (these pencils).
The complex proto-Slavonic case system is almost completely dissolved in modern Bulgarian. Vestiges are well preserved only in the personal pronouns and the masculine personal interrogative pronoun êîé (“who”), which have nominative, accusative and dative forms. Vocative forms are still in use for masculine and feminine nouns (however, not for neuter ones), but endings in masculine nouns are determined solely according to the stem-final consonant of the noun. In all other cases, except for a number of phraseological units and sayings, the proto-Slavonic case system has been replaced by prepositional and other syntactic constructions.
In modern Bulgarian, definiteness is expressed by a definite article which is postfixed to the noun (indefinite: ÷îâåê, “man”; definite: ÷îâåêúò, “the man”) or the first nominal constituent of definite noun phrases (indefinite: äîáúð ÷îâåê, “a good man”; definite: äîáðèÿò ÷îâåê, “the good man”), much like in the Scandinavian languages or Romanian. There are four singular definite articles. Again, the choice between them is largely determined by the noun's ending in the singular. Nouns that end in a consonant and are masculine use –úò/–ÿò, when they are grammatical subjects, and –à/–ÿ, when they are grammatical objects. Nouns that end in a consonant and are feminine, as well as nouns that end in –à/–ÿ (most of which are feminine, too) use –òà. Nouns that end in –å/–î use –òî.
The plural definite article is –òå for all nouns except for those, whose plural form ends in –à/–ÿ; these get –òa instead. When postfixed to adjectives the definite articles are –ÿò/–ÿ for masculine gender, –òà for feminine gender, –òî for neuter gender, and –òå for plural.