Some words consist of two successive vowel sounds within one syllable. These vowels are called diphthongs. With all diphthongs, the vowel starts with one sound and ends with another.
"AH" + "EE" as in Might
Examples of Diphthongs:
"OH" + "EE" as in Noise
"EH" + "EE" as in Pain and Weight
Try to keep the vowel as natural-sounding as possible, letting the second sound flow out of the first. Do not over emphasise the second sound of the vowel; allow it to disappear naturally.