Questions & Answers about Aqua deorsum e monte fluit et ad flumen pervenit.
Because aqua is the subject of both verbs: fluit and pervenit.
- aqua = water
- It is the thing that flows and reaches
So Latin uses the nominative case for the subject, just as English uses normal subject position:
- Water flows
- Water reaches the river
Deorsum means downward or downwards. It is an adverb.
It tells you how the water flows:
- Aqua deorsum fluit = The water flows downward
It does not change form, because adverbs in Latin do not agree with nouns.