Which one is correct?Twenty years (have/has passed) since my father died.
You should use "have", because the word "have" is plural. 20 is more than one, so it should go with a plural word. The word "has" is singular. You could say "One year has passed" because there was only one, not several.
As per the online resources, the correct term to use is the word 'have'. The correct grammatical sentence should be 'Twenty years have passed since my father died'.
I agree with pkioko. "have" is the word to use. "Years" is the subject, plural, and "have" is the verb that goes with a plural subject.