The One and Only Grammar Rule You Need to Know
If you never quite understood grammar and sentence structure, don't despair! In fact, we're not even going to ask you to remember all those rules of grammar. You just need to understand one basic concept in order to understand some basic English grammar and sentence structure, and it's this:
Complementary elements in sentences must agree.
Huh? What's this? Complementary elements are "things that go together." Think of the various sentence parts as a team. The parts need to run in the same direction in order to make a touchdown--in order to create meaning. There are different sets of teammates, and each set has to agree on its plays. So what are those "complementary elements" that function as teammates? There are seven different sets of things that must agree, whenever they occur in a sentence, in order for the sentence to make sense:
Well, you didn't think that we'd forget grammar terms completely, did you? But we think that you'll understand grammar and sentence structure more easily if you just have to remember that one, overall concept, "complementary elements in sentences must agree." 
