I like quick and simple explanations as you will appreciate. Especially when it comes to grammatical issues, in spite of the fact that there may be cases when one has to extend things a little further. I believe that things are learned little by little, and in studying foreign languages it is better to learn a more reduced usage of concepts and then widen it with the passing of time. I was always against having to study a mountain of rules from start to finish, then when the time comes to use them the rules are not going to be useful to me because I don't have a good command of the language.
In the first part of the book I have compiled 29 doubts that my students frequently bring up to me, or that I have had myself. The 29 are going to be of great help because they come up frequently when it comes time to use them in conversation as well as when it is time to take an exam.
Regarding the number of English expressions that I have chosen, I have noted a number of them that I feel are adequate, without being excessive or lacking. It is common to see the success of those posts or videos that have 400 phrasal verbs, but let's be honest. Not only will it be that no one is going to memorize those phrasal verbs, but there will be few people that will get to read them all.