It's very simple. Lie = to recline. So, now question comes “in” or “on” bed? well, let me clear. “On” is used for things or objects or materialistic things. “In” is used for people. For example: “ON” * Put this book on bed. read more
Lie in bed means you are under the covers - hence “in.” Lie on bed means you are on top of the covers/sheets - hence “on” “Lie in bed” is correct whereas you have to ad an article to “Lie on be”. read more
The main difference between the two words is that lay is a transitive verb, while lie is an intransitive verb. read more