Although this is a tricky one in terms of US/UK English with singular nouns seen to represent a group of people (sports teams being the classic example).

'Liverpool have won 6 European Cups so far' is correct usage in the UK, because 'Liverpool' refers to a group of 11 players at any one time, and a much larger squad and staff, operating as a single unit.

A US sports writer would say 'Liverpool has won', which in the UK would refer to the city, not the football team, as grammatically singular although it represents a far greater number of people.

Language, eh?