Expect means to think something will happen or believe something should occur. When you expect rain, you think it's going to rain, so you bring an umbrella. When your parents expect you home by dinner, they believe you should be there at that time.

The word carries a sense of anticipation based on evidence or experience. If you study hard for a test, you might expect to do well because your preparation makes success likely. If dark clouds gather, you expect a storm. These are reasonable predictions based on what you know and what usually happens in similar situations.

Expectations can also mean standards or requirements. When a teacher has high expectations, she believes her students are capable of excellent work and holds them to that standard. Your parents might expect you to clean your room or finish your homework: they're setting a clear standard for your behavior.

Sometimes people talk about exceeding expectations, which means doing even better than anyone thought possible. If you expect to score 85 on a test but earn a 95, you've exceeded your own expectations. When something falls short of expectations, it disappoints because it wasn't as good as anticipated.

The phrase “I expect so” means you think something is probably true, though you're not completely certain.