It has excellent sentences and doesn't use a lot of big words to define other words, nor does it give circular definitions (defining cat as an animal and an animal as a cat) but it does go into grammatical terms and usage notes that might be confusing if not properly learned. It's the first dictionary (besides the Webster's New World Dictionary of Basic American English, which is absolutely invaluable) that allows me to get a full understanding of a word without making me chase through twenty other words. It'd be 5 stars if it just didn't go into grammatical terms, but even those have to be understood to know how to use the word. I highly highly recommend it.