Are you using the (Red) or Intermediate (Blue) version? Is there a specific unit or tense you find confusing? Do you need practice exercises for a specific topic?
I can provide targeted explanations and examples to help you master those specific points. English Grammar in Use - Fifth Edition Grammar in Use - Pre-intermediate
Using much, many, a lot of, a few, and a little correctly with countable and uncountable nouns. Are you using the (Red) or Intermediate (Blue) version
Knowing when to use "I work" (habit) vs. "I am working" (right now). a lot of