She loses trust in Damon, partly because he killed her friend Aaron, so they break up, but soon get back together.
She eventually chooses Stefan in the season finale but before she can tell him, Elena drowns while having vampire blood in her system; she then awakens as a vampire in transition.
She grows closer to Damon while working together to save Stefan and try to defeat Klaus, eventually sharing a kiss.
She later admits to Stefan that she has feelings for Damon as well, but that she never stopped loving Stefan.
Stefan reveals that this woman caused the brothers to feud 145 years ago, and turned them into vampires.
He says that she was adopted and is actually a descendant of Katherine, and that he saved her the night of her parents' deaths.
In season four, Elena must decide whether to die or to feed on human blood so she can fully transition into a vampire.