Right now you are reading English. That means that you are using your brain in a very active way. Reading is a very active process. It is true that the writer does a lot of work, but the reader also has to work hard. When you read a text, you have to do some or all of these:

imagine a scene in your head
understand clearly what the writer is trying to say
agree or disagree with the writer
Advantages of Reading

When you learn a language, listening, speaking and writing are important, but reading can also be very helpful. There are many advantages associated with reading, including:

Learning Vocabulary In Context

You will usually encounter new words when you read. If there are too many new words for you, then the level is too high and you should read something simpler. But if there are, say, a maximum of five new words per page, you will learn this vocabulary easily. You may not even need to use a dictionary because you can guess the meaning from the rest of the text (from the context). Not only do you learn new words, but you see them being used naturally.

A Model For Writing

When you read, it gives you a good example for writing. Texts that you read show you structures and expressions that you can use when you write.

Seeing "Correctly Structured" English

When people write, they usually use "correct" English with a proper grammatical structure. This is not always true when people speak. So, by reading you see and learn grammatical English naturally.