They include exercises for your students. Some of the grammatical points covered are the following:
All vs All of ; Amount vs Number vs Quantit; Assure , Ensure, Insure, Secure; Between vs Amon; Causative verbs; Close (to) vs near (to)
Conditional sentences; Confusing words ; Either or / Neither nor; Even though / Even if / Even so; Lastly, Finally, Eventually, In the end , at last, etc..