"He likes to drink coffee with milk."
Translation:Anh ấy thích uống cà phê sữa.
Just to let you know, "cà phê sữa" most likely refers to the Vietnamese style of coffee where ground robusta beans are filtered into a glass with a bed of condensed milk using hot water, stirred up and then usually filled with ice due to Vietnam's climate.
If you google the term "Milk Coffee" you will find an entire Wikipedia entry where "ca phe sua da" is listed.
The word sữa is used as an adjective here just as milk is in the English term.
If milk is supposed to be used as an adjective, then the sentence should not read "with milk", which would mean the word milk is a noun in a prepositional phrase. Either we are learning the equivalent adjectives or the equivalent prepositional phrases. I'm not a coffee drinker in any case, so the term 'milk coffee' for educational purposes would be just fine for me if the intent here is to use 'milk' as an adjective.