在主动语态中,help后的不定式是可以省略的,但在被动语态中,这个to就必须加上(这好像是所有省略to和加上to的原则吧),是这样吧?比如:
主动:Working with native speakers helped me get a good grasp of the language.
被动:I was helped to get a good grasp of the language by working with native speakers.
另外,有趣的是,上面这个被动句中,by好像不一定理解成“被”了,而可理解成“通过”了,是这样吧?
完全同意你的理解和看法。
主动:Working with native speakers helped me get a good grasp of the language. 同当地人一起共事帮助我很好地掌握了这种语言。
被动:I was helped to get a good grasp of the language by working with native speakers. 同当地人一起共事帮助我很好地掌握了这种语言。