What's the enemy between Liverpool and Manchester United? Why do they hate each other?

Because they compete in the same league, they are both strong teams, and of course they are hostile to each other. It's not just them. As long as teams at the same level are like this, Manchester United also has great influence on Manchester City, Liverpool, Arsenal and Manchester United's Everton games. It's just that those weak teams 100 have enjoyed themselves occasionally in the Premier League for more than 0 years, but not as long as Liverpool, Manchester United and Arsenal, and they are not qualified to make enemies with them. Before Sir Alex Ferguson took over Manchester United in 1970s and 1980s, they were overwhelmed by Liverpool for a long time. The same is true of other leagues. AC vs Inter Milan, Real Madrid vs Barcelona, Ajax vs Eindhoven, Brazil vs Argentina, etc. These games are not all so-called vendetta and revenge.