It is no doubt that the grammar is a very essential part when you learn a language. In this case if you want to learn English is important to have a basic knowledge of grammar. A student should know much grammar as possible. It is important to study it, learn everything and know well the basics of the language, and if you do not learn the basics of the language, you can not speak English fluently.
Despite this, in my opinion, it is up to each person in what grade wants to learn English. For instance, if you just want to speak and understand English just to communicate with or just to understand a foreigner, I think you do not need to get to know a lot of grammar rules, tenses or very complex things. You’d need only to start with the most basic of the language and a lot of practice, and so, once you have mastered it, I think, it would be much easier to understand the structure of the grammar then, of course, only if you want to have a better standard of English and if you would like to use it for another purpose. It is better talk fluidly to want to say things very complicated or say them bad. This does not mean we do not have to study grammar; this is an option or method that I give to those who just want to learn for pleasure or pastime.
On the other hand, if you are someone who want to learn English for the purpose of getting a job or get something more profitable, for example, to be a teacher, it is indispensable and almost mandatory know everything about grammar.
Nowadays, forms of education have changed and they have necessarily to change to end the traditional way of teaching, it is no longer necessary to stay glued to a book of grammar, now, besides watching movies and series in English, listen to songs and read books there are many websites where there are very practical and understandable exercises, the idea is that everyone must have the intention and will to learn alone through the support of these exercises online.
check out these sites, I found them very useful and helpful.