Mastering formal structures often tested in advanced proficiency exams like Cambridge C1/C2 or TOEFL.
Unlocking the nuances of permission, obligation, probability, and past speculation (e.g., should have done vs. must have done ). Constantin-paidos-english-grammar-pdf
: Exercises force learners to choose between subtly different structures (such as Present Perfect vs. Past Simple). and past speculation (e.g.