1. Start with the shortest words:
* One letter: We have 'a', 'o', 'r', 'y' (4 words)
* Two letters: 'an', 'on', 'no', 'or', 'ar', 'ry', 'ay' (7 words)
* Three letters: 'cry', 'ran', 'any', 'ray', 'nay', 'oar' (6 words)
* Four letters: 'crony', 'roany' (2 words)
2. Longer words:
* There are no five, six, or seven-letter words possible using only these letters.
Total: 4 + 7 + 6 + 2 = 19 English words
Note: This list only includes common English words. There might be less common or archaic words that can be formed with these letters.