Learn Turkish: Kedi bugün bir uysal, bir hırçın. - Today, the cat is docile one moment, and cranky the next.

The bir ... bir ... structure is used to express alternating states or actions, translating closely to 'one moment... the next...' or 'sometimes... sometimes...'. In this sentence, it contrasts the adjectives uysal (docile) and hırçın (cranky) to describe the cat's rapidly shifting moods.

Why isn't there a verb or a 'to be' suffix at the end of hırçın?

In Turkish nominal sentences, the third-person singular present tense often implies 'is' without needing any suffix. You don't need a verb like oluyor (becomes) or the formal suffix -dır. The sentence is perfectly natural and complete just ending on the adjective.

Can bir ... bir ... be used with verbs as well as adjectives?

Yes, absolutely. While this sentence uses it to alternate between adjectives, you will frequently see it with verbs. For example, you could say Kedi bir uyuyor, bir uyanıyor to mean 'The cat sleeps one moment and wakes up the next'.

Is the comma required between the two alternating states?

Yes, a comma is normally placed between the two contrasting parts of a bir ... bir ... phrase. It mimics the natural pause in speech and helps separate the two alternating concepts clearly for the reader.