Questions & Answers about Мы услышали шум за дверью.
Why use the perfective verb услышали here instead of the imperfective слышали?
Услышать represents a sudden achievement of perception. While the imperfective слышать means the ongoing process of hearing (like 'we could hear'), the perfective услышать means you suddenly caught or registered the sound. Since hearing this noise was a single, spontaneous event, we need the perfective.
The preposition за can take different cases. Why does it take the instrumental case (за дверью) here?
When за means 'behind' and describes a static location (answering 'where?'), it requires the instrumental case. If it described motion toward a place behind something (answering 'where to?'), it would take the accusative case. Since the noise is just located behind the door, we use the instrumental form of the feminine noun дверь.
Why doesn't this sentence use a perfective infinitive, given the current lesson's focus on verbs of achievement?
This specific sentence uses услышали as the main verb with a direct noun object (шум), so there is no infinitive. However, услышать itself acts as a verb of achievement here! If you wanted to build an infinitive construction showing success (like in this lesson), you might say Мы смогли услышать шум (We managed to hear the noise), using the perfective infinitive услышать to show a successfully completed action.
Is there a difference between шум and звук?
Yes! Звук translates to a neutral 'sound' (like a musical note or a clear voice). Шум specifically translates to 'noise,' which usually implies a sound that is loud, unorganized, or disruptive.
Learn Мы услышали шум за дверью and more in Russian
All course content and exercises are completely free — no paywalls, no trial periods, no signup needed.
- ✓ Practice with interactive exercises
- ✓ Track your progress with spaced repetition
- ✓Learn at your own pace — completely free