Breakdown of Nu am cumpărat un cort, ci un sac de dormit.
un
a / an (m/n)
nu
no / not
avea
to have
dormi
to sleep
Questions & Answers about Nu am cumpărat un cort, ci un sac de dormit.
Why do we use de dormit instead of an adjective to say "sleeping bag"?
In Romanian, to describe what an everyday object is used for (its purpose), we use the preposition de followed by the supine form of a verb. The supine looks exactly like the past participle. So, un sac de dormit is the standard way to express "a bag for sleeping."
Could I use the infinitive and say un sac pentru a dormi instead?
People would understand you, but it sounds quite unnatural. When a verb modifies a noun to show its function (like a sleeping bag, washing machine, or waiting room), the standard Romanian structure is always de + supine (de dormit), rather than the infinitive.
If I bought two sleeping bags, how would I make un sac de dormit plural?
Why does the sentence use ci for "but" instead of dar?
You must use ci when you are completely replacing or correcting a negative statement. Since the first part of the sentence is negative (Nu am cumpărat un cort), and the second part tells us what was bought instead, ci is required. You use dar when you are just adding contrasting information without canceling the first part (for example: "I bought a tent, dar it is small").