When learning to cue English, beginners can easily be influenced by spelling. Instructors sometimes include lessons on trickier aspects on applying cues to the the pronunciation of words. Usually, time is designated to practice distinguishing /sssssssss/ and /zzzzzzzzz/. Another tricky aspect can be the various ways "-ed" endings are pronounced and cued. A common beginner error is to cue all words that end with -ed with the /ddddddddd/ phoneme. However, some words that end with -ed actually end with the /ttttttttt/ phoneme.
So, what’s the pattern for past tense (-ed) words?
1) If the root word ends in /ttttttttt/ or /ddddddddd/, the [-ed] ending is pronounced (cued) /ɪĭiɪĭiɪĭiddddddddd/, /ed/, or /əəəəəəəəəddddddddd/.
Examples: waited knitted voted
/wae, tid/ /ni, tid/ /voe, tid/
Folded worded needed
/foe, l, did/ /wur, did/ /nee, did/
2) If the root word ends in a voiced sound other than /ddddddddd/, the [-ed] ending is pronounced (cued) /d/.
Examples: bored paged called learned
/boe, r, d/ /pae, j, d/ /kaw, l, d/ /ler, n, d/
3) If the root ends in a voiceless sound other than /t/, the ending is pronounced (cued) /t/.
Examples: worked watched fished sipped
/wer, k, t/ /wah, ch, t/ /fi, sh, t/ /si, p, t/