She competes with her best friend. 她和她好友互相竞争.\x0dBusinesses compete with each other. 许多企业互相竞争.\x0dCompete with 与 Compete against 其实意思完全一样,不同点就是含有的感觉.\x0dAre you with me or are you against me ? 是个很好的例子.这里"with"很先然的比较友善."against"带有敌对的态度.\x0d打个比方,当人们"compete with each other" 时他们会很友善,对方的成功会得到认可,也会影响到对手的发展（可以学习）,共同获利.\x0d当人们"compete against each other" 时他们态度恶劣,恨不得对方失败,也不会去恭喜人家.所以在你写句子的时候要看是哪一种态度和感觉来选择要用哪个.\x0dChina and Japan compete against each other.\x0d中国与日本互相竞争.\x0d加拿大与美国互相竞争.