Is this sentence correct? Do or does? [closed]

"I am hoping for an idealistic world which do/does not exist"

What should I use here? Do or does? Also please tell where do I learn these basic concepts?


Solution 1:

"Does"

Rule: Singular nouns (an idealistic world) take singular verbs (does) after them; Plural nouns (idealistic worlds) take plural verbs (do) after them.