An example of really used as an adverb is is someone saying they really want to do something, meaning they want to do something very much.
There isn't really a lake there; it's just a mirage.
That was a really enjoyable evening.
Really, I don't want more dessert.
But ma, I really, really want to go to the show!
I would really like to meet your sister.
“I've been reading her diary.” “Really?”
A really hot day.
"He really is a true friend." / "Really? What makes you so sure?"
A: That girl talks about herself way too much.
B: Really. She's a nightmare.
Origin of really
- real +"Ž -ly