What words have 2 vowels next to each other?

You're asking for words with diphthongs, which are two vowels that make a single sound. Here are some examples:

Common Words:

* About

* Again

* Boat

* Break

* Chair

* Coin

* Fail

* Fruit

* House

* Join

* Loud

* Mouse

* Pain

* Quiet

* Said

* Train

* Voice

Less Common Words:

* Adieu

* Beige

* Bellow

* Cower

* Fiasco

* Feign

* Glower

* Hie

* Lousy

* Moi

* Prow

* Sleigh

* Spouse

* Vow

Important Note: This list is not exhaustive, and there are many more words with diphthongs!