When ever you have a vowel that sounds just like its name we call it a "Long Sound" or "Long Vowel". Look at the word "Kite". Sound it out. The "i" sounds just like the vowel itself. Long "i" can also come from the letter combination of i_e, igh, le, and plain old -y. Such as in the word "fry". Cool fact the word "set" has the most definitions of any other word in the English language. The best way to identify how a vowel is used in a word is to say the word aloud. You may need to say it several times to make sure you can listen to yourself talk. Learning how pronunciation words that include short vowels is often a tall order for non-native speakers because it differs from the fundamental phonetic sounds that were learned early on. You will see that is where different accents also come off of words.
The most common long "I" words are: ice, five, bike, mice, nice, nine, side, wide and fine. The most common short "I" words are: big, did, his, lip, pin, pig, sit, sip and zip (had to get a "z" in there!) Scroll down to print out some great worksheets to help you determine the differences. These worksheets will start by having you identify the vowel sounds that are present in words. They will move on to help you sound out and understand words that may be new to you. There are a bunch of fun activities that will help motivate students along the way. There are some shading, coloring, and puzzle sheets along the way.