Breakdown of Наблюдение за циклом сна в лаборатории заканчивается под утро.
в
in / to (direction)
утро
morning
заканчиваться
to end (imperfective)
лаборатория
laboratory
Questions & Answers about Наблюдение за циклом сна в лаборатории заканчивается под утро.
Why is под утро used here instead of just утром, and what case is утро in?
The preposition под followed by the Accusative case is used to express an approximate time, meaning 'towards' or 'approaching'. While утром means the action happens during the morning, под утро implies it happens very late at night, just as morning is approaching. Because утро is a neuter inanimate noun, its Accusative form is identical to its Nominative form.
Why do we use за циклом instead of just the Genitive case to say 'observation of the cycle'?
The noun наблюдение (observation) inherits its grammar from the verb наблюдать (to observe or watch). In Russian, you 'watch after' something using за + Instrumental case. Therefore, 'observation of the cycle' translates to наблюдение за циклом, rather than using a direct Genitive construction.
What is the dictionary form of сна, and why does it look so different here?
The dictionary form is сон (sleep). It is in the Genitive case here to express 'of sleep' (цикл сна). The word сон contains a 'fleeting vowel'—the -о- disappears when case endings are attached, leaving the root сн- followed by the Genitive ending -а.
Why is the imperfective verb заканчивается used here instead of a perfective verb like закончится?
The imperfective aspect is used because this sentence states a general routine or recurring fact about the laboratory's procedures, rather than a one-time completed action. It means the observation generally ends towards morning every time they run the sleep cycle.