- I went to the cinema last night
The word "the cinema" here is an object or an adverb?
- We live in a house
The word "a house" here is an object or an adverb?
- I went to the cinema last night
The word "the cinema" here is an object or an adverb?
- We live in a house
The word "a house" here is an object or an adverb?
[1] I went to the cinema last night.
[2] We live in a house.
In [1] "the cinema" is a noun phrase functioning as object complement of the preposition "to". Note that "to the cinema" is a preposition phrase functioning as complement of the verb "went".
In [2] "a house" is a noun phrase functioning as object complement of the preposition "in". Note that "in a house" is a preposition phrase functioning as complement of the verb "live".