Questions & Answers about Я недолго ждал у входа в театр.
Here недолго means not for long or for a short time. In natural English, this sentence is often translated as I didn’t wait long at the entrance to the theater.
It describes the duration of the waiting, not the result of the action.
In this sentence, недолго is normally written as one word because it functions as a single adverb meaning for a short time.
A useful rule of thumb:
- недолго = a regular adverb with the meaning for a short time
- не долго = separate spelling when the speaker is emphasizing the negation itself or making a contrast
For example:
- Я недолго ждал. = I waited only a short time.
- Я ждал не долго, а всего пару минут. = I didn’t wait long, only a couple of minutes.
In your sentence, the fused form недолго is the most natural.