Breakdown of Улитка ползёт вверх по стволу дерева.
дерево
tree
по
along, around
вверх
up, upwards
ползти
to crawl
Questions & Answers about Улитка ползёт вверх по стволу дерева.
Why use ползёт instead of ползает here?
Ползёт is the unidirectional verb (from the infinitive ползти). It is used here because the snail is making a single, directed movement (straight up) at this specific moment. If the snail were crawling aimlessly all over the tree, we would use the multidirectional verb ползает.
Why do we use вверх по стволу instead of на ствол to mean 'up the trunk'?
Using на ствол (Accusative) would mean the snail is crawling onto the trunk from somewhere else. Because the snail is already on the trunk and progressing along its surface, Russian uses по + Dative (по стволу) to mean 'along'. The adverb вверх (upwards) is simply added to specify the direction.
Could I use наверх instead of вверх here?
They are very similar, but наверх usually implies moving towards a specific destination (to the top), whereas вверх focuses purely on the upward direction of the movement. Since we are describing the ongoing direction along a surface, вверх is the more natural choice.
Why is дерева in the Genitive case?
It literally translates to 'of a tree'. The word ствол means trunk, so ствол дерева means 'trunk of a tree'. The Genitive case is used here to link the two nouns and show association.