Here's what you need to know:
* Common examples: "food", "moon", "train", "feet", "boot"
* Sound: The double vowels often create a long vowel sound (like the "oo" in "moon" or the "ee" in "feet").
* Spelling: The two vowels together can represent a single sound (like "oo" in "moon") or a diphthong (like "ai" in "train").
It's important to note:
* Not all double vowels create long vowel sounds. Some double vowels are part of a diphthong, which is a combination of two vowel sounds.
* Double vowels can be tricky. There are rules and exceptions to how they are pronounced.
If you're having trouble with double vowels, it's best to consult a dictionary or a grammar guide.