Reading in mind

To whom it may concern,

As a students whose first language is not English, I find it quite difficult to manage all the proper rules there are in learning English. Sometimes I tangled myself in questions about English grammar. However, I keep on trying with a hope that one day I can master all the proper rules and be able to speak English even better than people whose first language is English.

One of the ways to achieve this goal is through reading. I find it very helpful to read, although yes, sometimes I lost myself in between of words that make up a beautiful long sentence. The only problem is, I still cannot yet manage to read in mind. I feel better to read things aloud. But I notice that many professors do not read books with their lips moving at all. So my question is, "How do I learn to read in mind to capture as good of an understanding as I read with my lips moving?"

Thank you.