"Bonan matenon, kara!"
Translation:Good morning, dear!
Learning Esperanto has made me realise how little understanding I have of English grammar.
When would you use "kara"? Is it just for informal friends or can you use it with strangers as well, for example walking on the street and saying good morning to someone?
i'm really not too sure, so i wouldn't go by my advice before checking with someone else, but to me it seems like "dear" is meant for a loved one.... like a spouse/child/good friend. i wouldn't ever call a stranger dear
"Bona mateno" = a good morning (as the subject of a verb)
"Bonan matenon" = a good morning (as the object of a verb)
It is singular but in the accusative case. (Plural would be "bonaj matenoj" in the nominative or "bonajn matenojn" in the accusative.)
-n is the case marker for accusative; -j is the number marker for plural.
"Bonan matenon" is in the accusative here because it's an expression that's short for something like "(I wish you) a good morning", so it's the object of an implied verb.
Yes, "Bonan matenon/tagon/vesperon/nokton", also "dankon", "bonan apetiton", and others.
Same in German, incidentally: "(ich wünsche dir einen) guten Morgen/Tag/Abend/Appetit".
"Nacht" is feminine, "Tag/Morgen/Abend/Appetit" are masculine.
And the feminine accusative looks like the feminine nominative, so you can't tell that it's accusative, but it still is :)