"They drink delicious coffee."
Translation:Ili trinkas bongustan kafon.
The rule to start with:
A noun is either
the subject of the sentence -> no accusative
the direct object of the sentence -> accusative
some other part of the sentence -> marked by a preposition
The sentence "Ili trinkas bongustan kafon." as one noun (kafo) which is the direct object and therefore marked with accusative.
I guess the sentence about milk you are referring to was something with "da". For example:
Mi prenas iom da lakto por mia kafo.
Here we have two nouns: "lakto" and "kafo". Both are marked with a preposition "da" and "por". Therefore no accusative.
That's the basic rules. There are other roles than accusative can indicate, so it's a bit more complicated, than what I describe here. But that's the rule to start with.
P.s. I was feeling this way and had to read over the notes again to catch my miss.
From Tips & Notes:
Note: the direct object -n ending (accusative) is not used after da or de.
So yeah, anytime you see something with a da/de in front of it you're not going to have an accusative ending regardless of if it is accusative or not. :D
Hope this helps.
Let me just try and make something clear here. I'm no linguist, so it may not be the best of explanations. Anyway. There is, in every sentence, at least a subject. A verb relates the subject to something, and that something is called the direct object. So, when I say "Sofia drinks coffee", "coffee" is the direct object, since it is what Sofia is drinking. However, the direct object may be complemented by information, such as in "Lidia drinks a cup of tea". The cup is what Lidia drinks from, that's the direct object. "Of tea" is merely additional information. The accusative is placed on the direct object. The example sentences I used would be, in Esperanto: "Sofia trinkas kafon" "Lidia trinkas tason da teo"