Homophones are words that share the same pronunciation regardless of spelling.
missed-mist
peak-peek
rays-raise
tolled-told
The use of homonyms can be useful to alleviate interference students sometimes experience from spelling. For instance, if a hearing student is having trouble buying into the idea that -ed can be pronounced as /t/, then the homophone pair missed-mist can provide a point of comparison.
Pairs like days-daze, does (i.e., female deer) -doze, grays-graze, gays-gaze, Oohs-ooze, pries-prize, and sighs-size can help focus students to the pronuncition of final -s as /z/ in spite of its spelling.
In parts of the Western U.S., like Utah, a vowel merger has occured and the distinction between / / and / / has been lost. The use of honophones can be useful in a class to suss out which students will use the chin placement for / / and which will not. For example, by offering pairs like cot-caught, rot-wrought, knotty-naughty, the instructor can ask students, "Are these words pronounced the same or differently?" For students from the mid-Atlantic region for example, these words will be pronounced differently. For cuers from Utah, Idaho, and parts of California, they might be pronounced the same.
Mary-merry-marry