The answer is, “Do more academic reading.”
You need to look at real academic documents and analyse them for meaning. Try to insert your own subheadings and summarise the documents within 200-300 words. Underline key words and add new vocabulary to your word cards.
Where can you find academic documents? In your local college library, sometimes in your city library and on the internet.
If you are a college or university student, your institution’s library may give you access to JSTOR or other online document libraries.
If you are not a higher education student Google Scholar should be your first choice to search academic documents.