Long vowel sounds are the name of the letter, such as the A in tape or the O in snow. When distinguishing between a long and short vowel, determine if the vowel sounds like the name of the letter itself, and if so, it is a long vowel.
McGraw-Hill, a leader in providing educational materials since 1917, defines long vowels as a vowel that says its name. Examples of this are the A in cape, the E in speed, the I in tile, the O in spoke and the U in fuse. Each of these words involves the letter sound of the vowel sounding like the name of the letter. For example, when a vowel is at the end of a word, such as be, it is usually a long vowel sound.
PhonicsOnTheWeb.com offers a useful lesson on the use of long vowel sounds. This site has several examples of each of the long vowel sounds. There are also interactive lessons that are available to help teach the long vowel sounds, available for free on MacMillanmMH.com. Both these sites explain in a clear and concise way that long vowel sounds are made when the vowel sounds like the name of the letter. MacMillanmMH.com also has five short poems to help encourage the memorization of the long vowel sounds.