Questions & Answers about Ĉiu persono ricevas unu semon.
A word-by-word breakdown:
- Ĉiu = each / every
- persono = person
- ricevas = receives / gets
- unu = one
- semon = seed as the direct object
So the structure is basically:
Each person receives one seed.
The -n marks the direct object in Esperanto.
Here, the thing being received is the seed, so semo becomes semon.
- semo = seed
- semon = seed as the object of the verb
This is very common in Esperanto:
- La knabo vidas hundon. = The boy sees a dog.
- Mi havas libron. = I have a book.
In your sentence, unu semon is the thing each person receives, so it gets -n.