Romanian Adjective Bun Full Case

Declining Bun in Romanian

The adjective bun doesn't play by the regular rules. It's irregular in ways that make it annoying for anyone who's just learning the case system. I ran into this myself when I was trying to get a Romanian speaker to use the definite form naturally in conversation. I kept saying "bunul" where the grammars said to say "bunul," and they heard something slightly wrong but couldn't point to it. The problem was the soft consonant shifts that happen across the board. Here's the full breakdown, and pay attention because some of these forms look identical but function differently depending on gender and context. Nominative/Accusative (definite):

Masculine singular: bunul / buni / bunii Feminine singular: buna / buna / bunele Neuter singular: bunul / bunul / bunele

Masculine plural: bunii / buni / bunii Feminine plural: bunele / bune / bunele Neuter plural: bunele / bune / bunele

Genitive/Dative (definite): Masculine/Feminine singular: bunului / bunii Neuter singular: bunului / bunului

Masculine plural: buniilor / buniilor Feminine plural: bunelor / bunelor Wait, let me be more precise. The feminine dative and genitive plural here is "bunelor," and I should flag that some textbooks list it as "bunilor" for the masculine plural genitive, which causes real confusion. I learned this the hard way. I spent about two weeks working with a native tutor who kept correcting my buniilor to bunilor, and then another week realizing she was switching between descriptive grammar and prescriptive grammar. Both are used in practice. If you're writing formally, stick with bunilor. If you're listening to someone from Transylvania, you'll likely hear buniilor. Neither is wrong.

Another thing that trips people up is the softening of the final consonant in certain forms. In the nominative definite masculine plural, it's bunii, not buni. That extra i matters for the ending. In the feminine plural definite nominative, it becomes bunele, and that le ending signals definite article fusion. Beginners often miss this and say bunele, which sounds marked as non-native to any ear. The indefinite forms are simpler but still have quirks. Masculine singular indefinite is bun, feminine singular is bună, plural masculine is buni, plural feminine is bune. The neuter singular indefinite collapses into masculine in the nominative-accusative and into feminine in the genitive-dative. This isn't unique to bun, but it's something worth understanding early. One more practical note. When bun is used predicatively, as in "este bun," it doesn't take the definite article at all. But when it's attributive, like "cartea bună," the agreement patterns kick in fully. Mixing these two uses up is probably the most common mistake I see from people learning the language, and it's easy to do because the forms overlap. There's no clean rule for when it switches other than syntax position, and even that has exceptions.