Breakdown of Она осторожно идёт по лестнице.
она
she / it (for a feminine noun)
идти
to go (on foot) / to proceed, go (of a process)
осторожно
cautiously, with care
по
along, around
Questions & Answers about Она осторожно идёт по лестнице.
The translation says "on the stairs". Why use по instead of на?
In Russian, when you are talking about movement along a surface, you use по followed by the Dative case. While на (plus the Prepositional case) would mean a stationary location like "standing on the stairs", по captures the active movement of walking up, down, or across them.
What case is лестнице in?
It is in the Dative case, which is required here by the preposition по. The dictionary form is лестница (stairs/staircase), which is a feminine noun. To form the Dative case, the ending -а changes to -е.
Why does this sentence use идёт instead of ходит?
идёт is a unidirectional verb of motion, meaning the action is happening right now in one ongoing direction. Because she "is walking" on the stairs at this exact moment, we use идёт. If we wanted to say she walks on the stairs regularly as a habit, we would use ходит.
Is the letter т in лестнице pronounced?
No, the т is silent. In Russian, when the consonant cluster стн appears in a word, the т is almost always dropped in speech to make it easier to say. You pronounce the word as if it were written "леснице".