Regular past tense verbs have either a voiced or unvoiced -ed ending. This will be an important distinction when teaching pronunciation to English as a Second Language or English as a Foreign Language students.
The "-ed" endings of regular past tense verbs are pronounced in three different ways. They end with either a /t/ sound, a /d/ sound, or an /id/ sound. Verbs ending with an /id/ sound are easier to teach. Determining whether a past tense verb ends with a /t/ or /d/ sound is more difficult for ESL students.
To determine whether a Simple Past tense verb has a voiced or unvoiced –ed ending, we look at the final sound at the end of the base form of the verb (before you add –ed to the verb). This tells us if the verb ending should be pronounced as a /t/ or a /d/. For example, for the word "work," the "k" sound (not the letter sound) determines that the ending for "worked" is pronounced "work/t/"; for the word "clean," the "n" sound determines that "cleaned" is pronounced "clean/d/."
"Voiced Sounds" Have a /d/ Ending
To distinguish a voiced sound, I have the ESL student determine the final sound of the base form of the verb (before adding the –ed). For example, for the verb "save," "save" is the base form and the final sound is "vvvvvv." I then ask the student to hold three fingers to their throat and make the sound "vvvvvv." I ask them if they feel a vibration in their throat. If there is a vibration, then the ending is pronounced as a /d/: save/d/.
"Voiceless Sounds" Have a /t/ Ending
To distinguish an unvoiced (or "voiceless") sound, again, I have the student determine the final sound of the base form of the verb (before adding the –ed). For example, for the verb "miss," "miss" is the base form and the final sound is "sssssss." I then ask the student to hold three fingers to their throat and make the sound "sssssss." I ask them if they feel a vibration in their throat. If there is no vibration, then the ending is pronounced as a /t/: miss/t/.
When using this method in a lesson to teach pronunciation of Past Tense verbs and whether the verb has a voiced or unvoiced -ed ending, you really need to demonstrate the way to determine if the sound vibrates or not. Adult ESL students sometimes feel self-conscious or are otherwise reluctant to put their fingers to their throats and make funny sounds. So I consistently model what the student should do, especialy when deteriming whether there is a voiced or unvoiced -ed ending.
The mistake students usually make during this pronunciation lesson is that they look at the last letter and say the letter, rather than make the sound that the letter makes.
See
Voiced and Unvoiced Sounds
for more information about teaching ESL students voiced or unvoiced –ed endings and for the general concept of voicing.
