Positional Orthography of Long ā (ai vs. ay):
• Interior <ai>: In English base words, ai almost invariably occurs in the interior of a syllable before a consonant (sail-or, fail-ure, faith-ful, dain-ty, dai-sy).
• Final <ay> & Suffixation: At the end of English root words, long ā is represented by ay (stray, play, stay, say, pray). When adding vowel suffix -ing, the final y is preserved without change: straying, playing, staying, saying, praying.
Digraph Equivalence for Long ē (ee vs. ea):
• Both <ee> and <ea> represent the high front tense vowel /iː/.
• <ee> (Germanic Origin): Typically represents historical long vowels in native Old English words: feeble (OF), needle (OE), sweetly, weekly, heedless, cheerful.
• <ea> (Open & Diphthongal Roots): Often traces to Old English diphthongs or Anglo-French imports: easy (OF), eager (OF), eagle (OF), leafy (OE), nearly, eating.