Ordinal Numerals

The ordinal numerals (ðåäíè ÷èñëèòåëíè), just like the adjectives, are used as attributes in the sentence. They agree in gender and number with the nouns they qualify, so they have forms for the three genders and for the plural, and they can join the definite article. The forms for the ordinal numerals, as a rule, are derived from the form for the cardinal number by adding endings -È, -À, -Î, -È for the masculine, the feminine, the neuter and the plural. Here are some examples (the accented vowel is underlined):

ïåò - ïåòÈ, ïåòÀ, ïåòÎ, ïåòÈ (fifth)
øåñò - øåñò
È, øåñòÀ, øåñòÎ, øåñòÈ   (sixth)
ñåä
åì - ñåäìÈ, ñåäìÀ, ñåäìÎ, ñåäìÈ   (seventh)
î
ñ
åì - îñìÈ, îñìÀ, îñìÎ, îñìÈ   (eighth)
äåâåò - äåâåò
È, äåâåòÀ, äåâåòÎ, äåâåòÈ   (ninth)
äåñåò - äåñåò
È, äåñåòÀ, äåñåòÎ, äåñåòÈ   (tenth)
òðèäåñåò - òðèäåñåò
È, òðèäåñåòÀ, òðèäåñåòÎ, òðèäåñåòÈ (thirtieth)

However, not all the ordinal numerals are derived like this. The ordinal numerals for the 'hundreds', for 'õèëÿäà', 'ìèëèîí', 'ìèëèàðä' are derived by adding the suffix -EH (the E disappears in the forms for the feminine, the neuter and the plural):

ñòî - ñòîòåí, ñòîòíà, ñòîòíî, ñòîòíè   (hundredth, 100th)
õèëÿäà - õèëÿä
åí, õèëÿäíà, õèëÿäíî, õèëÿäíè   (thousandth, 1,000th)
ìèëèîí - ìèëèîí
åí, ìèëèîííà, ìèëèîííî, ìèëèîííè   (millionth, 1,000,000th)
ìèëèàðä - ìèëèàðä
åí, ìèëèàðäíà, ìèëèàðäíî, ìèëèàðäíè (billionth, 1,000,000,000th)

The ordinal numerals for 200 and 300 - 'äâåñòîòåí' ('two-hundredth', 200th), 'òðèñòîòåí' ('three-hundredth', 300th) sound clumsily and are barely used.

The ordinal numerals for 1, 2, 3, 4 are more or less irregular. Here they are:

1 - ïúðâè, ïúðâà, ïúðâî, ïúðâè   (first)
2 - âòîð
è, âòîðà, âòîðî, âòîðè   (second)
3 - òðåò
è, òðåòà, òðåòî, òðåòè   (third)
4 - ÷åòâúðò
è, ÷åòâúðòà, ÷åòâúðòî, ÷åòâúðòè (fourth)

In the complex forms of the ordinal numerals - all numbers over 20, only the last numeral is ordinal. It changes in gender and number, and joins the article, if needed. Here is an example:

123 - ñòî äâàäåñåò è òðåòè(ÿ(ò)) /òðåòà(òà) /òðåòî(òî) /òðåòè(òå) ((the) one hundred twenty third)

Katina Bontcheva. Elementary On-Line Bulgarian Grammar. 1999