Hello,
When we take a look at English test prep books that are specially designed for ESL learners, we often see in their title that the book is for "learners at elementary level", "learners at intermediate level", and "learners at advanced level".
When we compare the English of a child native English speaker and that of an adult native English speaker, we see that the adult native speaker's English is more "advanced" compare to the child. When we take a look at K-12 English Language Arts curriculums, we can say that the curriculum progresses from "elementary English" to "advanced English" as the grade level goes up.
But to me all these are very vague ideas. What exactly are the characteristics of "elementary English" and "Advanced English"? What exactly are the differences between "elementary English" vs. "advanced English"? How are the terms "elementary English" and "advanced English" defined?
I don't have much background in Linguistics, so if my question could sound a bit funny, but thank you for your understanding.