Pronunciation rules for vowel combinations oi and oy

Combination of vowels Pronunciation Example words Example word pronunciation My own example words
oi /oi/ voice /vois/
oy /oi/ boy /boi/
oy·ster /’oi-stər/

The following sentence includes the pronunciation /oi/ of the combination of vowels oi and oy, please memorize this sentence:
The boy enjoyed playing with the toy oysters made of coins. The boy enjoyed playing with the toy oysters made of coins.