"Good morning, how are you?"
Translation:Bonan matenon, kiel vi fartas?
Zamenhof took it from the German fahrt, which means "journey". It's cognate with the English "fare".
Of course, there is a natural language where "fart" means something else.
or maybe he took it from the nordic languares where it is spelled 'fart' without the 'h' and which is globally used nowadays in the runners community in name for a popular training method, 'fartlek'. fart = speed . btw in French and Spanish you say ''how are you going?'' for 'how are you?' as well, so it is not that far(t) fetched.
It's the present-tense conjugation of "farti", which is essentially the English "fare". "How are you faring?"
and if you're also not familiar (like me) with "fare" in this sentence, perhaps you heard it as "farewell" or "fare thee well", i just learned. in english, it means to proceed or get along.
it's also interesting to notice the similarities with "fari", in esperanto: https://esperanto.stackexchange.com/questions/4771/difference-between-fari-and-farti
Adverbs end in -e.
Adjectives end in -a.
Any noun/adjective (except for "la") that's in the accusative (direct object of a transitive verb) gets the -n suffix.
The greeting is "bonan matenon" because it's short for something like "I bid you a good morning" or "I hope you have a good morning" or something along those lines.
It's not a direct object. A direct object is the one receiving the action (i.e. in "Mi amas vin", "vin" receives the action "amas" given by the subject "mi"). But "vi" here is the subject and is the one that does or experiences the action, so it can't be in the accusative case.