1. Haggen is not a proper English word. It is a name created.
2. Alphabets and Sounds do not follow straight patterns or rules.
Rules are only guidelines, and they are 80% correct.
E.g., get, budget ==> same get, but different sounds.
3. The purpose of learning rules is get some ideas. In the end, you
need to learn the words, and accept their sounds.
This is why EasyPhonics, we have exercises for you to learn
the words with the sounds. After you practice all the words,
basically, you are competent with the sounds.
Don't be afraid of mistakes. If you can guess >80% correct, this is
very good already.
(Jacko, please translate this message into Chinese).