Here's a breakdown of some common scenarios:
1. Diphthongs:
* Two vowels create a single sound: Examples include "oi" (boy), "ou" (out), "ai" (rain), "ea" (meat), "au" (haul).
* These combinations often represent a single vowel sound, not two separate ones.
2. Vowel Digraphs:
* Two vowels represent a single vowel sound, but the sound isn't always the same as either of the individual vowels. Examples include "ee" (see), "oo" (moon), "ie" (pie), "oa" (boat).
* These can sometimes be tricky, as the sound they make might be different depending on the word.
3. Separate Vowel Sounds:
* Two vowels can be pronounced separately in words like "aeronautics", "aviation", "radio".
* This usually happens when the vowels are in separate syllables.
4. Vowel Pairs for Silent Letters:
* Sometimes two vowels appear together, but one is silent. Examples include "ai" in "rain" (the "a" is silent), "oa" in "boat" (the "a" is silent).
* These combinations are often a matter of spelling conventions.
In Summary:
The interaction of two vowels in a word can be quite complex. There's no single rule, but understanding the different scenarios will help you decipher their pronunciation in different situations.
Remember: The best way to understand how two vowels will sound is to pay attention to how they are pronounced in specific words. You can also use a dictionary to confirm the pronunciation.