Correction : It is "FAIL" not FELL. Fell is the past tense of FALL. Now, to improve your hearing and understanding ability, you need to do a lot of practice. You need to hear English a lot. I recommend you to start watching English movies, documentaries, Cartoons or sitcoms. Reading and listening are completely different abilities and hearing more English is the only solution to your problem. You need to make your ears attuned to picking out English words from speech. This will only come with practice. read this site : http://esl.about.com/od/englishlistening/a/listen_tips.htm