In my English b1 level I learned some gramatical rules that  were not neccesary like conbinig verbs with others in the infinitive (to + verb) or in the gerund (verb + ing), depending on the main verb. For example, enjoy requires a gerund (I enjoy reading), while want uses an infinitive (I want to learn). However, for me, this type of grammar teaching is unnecessary, since it makes no sense for it to be presented as a formal rule if in the end it is only internalized when speaking and interacting. It's frustrating that there is so much emphasis on theory when true language acquisition comes from practice and natural exposure.