Questions & Answers about После долгой прогулки я чувствую усталость в теле.
In Russian, the preposition после (after) always takes the genitive case.
- прогулка (a walk) – nominative, feminine singular
- прогулки – genitive singular of прогулка
- долгая (long) – nominative feminine singular
- долгой – genitive feminine singular
So:
- после прогулки = after the walk
- после долгой прогулки = after a long walk
Both the noun and the adjective must be in the genitive singular, which is why you see долгой прогулки, not долгая прогулка.