this case belongs to me 为什么belong要加s 是因为this case是第三人称吗

this case belongs to me 为什么belong要加s 是因为this case是第三人称吗 This dress belongs to my sister.为什么是belong+s This case does not belong to me! 看下这句This case doesn't belong to me 请教This case doesn't belong to me This case doesn't belong to me与These keys don't belong to hi This factory produces steel 中为什么produce 要加S 是因为第三人称单数吗 Do与Does的区别?This case doesn't belong to me.This case don't be This case doesn't belong to me!这句中to起到什么作用? it is belongs to me belong后面为什么要加s The car is belongs to me.为什么belong要加s? 为什么是belongs to me,而不是belong to mine呢?