英语句子语法问题

问题描述:

英语句子语法问题
some usages are “prescribed”,to be learntand followed accurately; other are “proscribed” ,to be avoided.
逗号加to的用法是什么用法?

不用逗号 也可以 这是动词不定式的被动形式作主补
原句= Some usages are ”prescribed” to be learnt and followed accurately while others are “proscribed” and should be avoided.