kobo aura h2o save new word

Hi guys,
from 4 days ago i have buy my new kobo aura h2o, and i'm very happy about it, but i'm not completely happy because i have some problem using touch screen (when i want select a phrase for example, sometimes it's very slowly, sometimes change page after two or three taps and i believe that with some software implementation features this device will be the best!

for example i would save the words that i don't know, is it possible?
If yes how can do it, please?

Thank you for your attention,
Byeeee.