In-depth English Grammar Concepths

This is "In-Depth English Grammar Concepts," focusing on the essential core grammar required for mastering English. 

By isolating only the functional vocabulary of English grammar and connecting "one word to one clear concept," we help you naturally absorb the structure of the language. 

Once you understand the derived roles and operational concepts of basic verbs, prepositions, modal verbs, functional words, sentence structures, and modifiers, they will automatically work for you like a perfect formula in every sentence you encounter.