Main spellings (~99%)
⟨d⟩ ~98%
The letter ⟨d⟩ covers most words with the /d/ sound.
Doubled consonants: When ⟨dd⟩ appears in the middle of a word, it still makes just one /d/ sound. Examples: middle, sudden, ladder.
⟨ed⟩ ~1%
The past tense ending ⟨-ed⟩ is pronounced /d/ after voiced consonants and vowels.
-ed pronunciation rule: Say /d/ after voiced sounds (called, played), say /t/ after voiceless sounds (walked, stopped), and say /ɪd/ after /t/ or /d/ (wanted, needed).