Never Learned
"You've never done it?" asked Kíli incredulously. "Ever?"
"There is no place to do so in the Forest," Tauriel told him, smiling softly. "And there were always more important things to attend to."
"So, you never even learned how?"
"I have never had the need to learn, so the issue has never come up."
"But... what if something had happened in Laketown? What if..." Kíli stopped, rubbing his chin thoughtfully; then he grabbed Tauriel's hand and tugged on her. "Come on!"
"Where are we going?" she asked.
"To the Lake! You're about seven hundred years overdue for a swimming lesson."