-s and -ed Phonics Investigation - Answers!

Last week we talked about the different sounds that are made by the endings -s and -ed when they are added onto a base word.  The challenge has come to and end and it's time for answers and shout-outs!

Last week's challenge questions:

1. Can you figure out what the relationship between the /s/ and /z/ sounds of the -s or the /t/ and /d/ sounds of the -ed is?
2. Can you notice any patterns in the base word (the word that you add endings to) that will give you an idea about whether the -s will say /s/ or /z/ or whether the -ed will say /ed/, /t/ or /d/?
3. Bonus: One of these endings is more complicated to pronounce today than it was a hundred or two hundred years ago.  Do you know which one and how it has changed?

Answers:

1. /s/ is the unvoiced version of /z/ and /t/ is the unvoiced version of /d/.
2. The sound that -s or -ed make when added on to a base word depend on whether the base word ends with a voiced or an unvoiced sound.  For example...
   
   "cat" ends with an unvoiced sound (/t/) and so the -s added to the end makes an unvoiced sound (/s/) also, whereas "dog" ends with a voiced sound (/g/) so the -s also makes a voiced sound (/z/)
   
   "stay" ends with a voiced sound (/ā/ - vowels are always voiced) so when you add -ed it also makes a voiced sound (/d/).  "pack" ends with an unvoiced sound (/k/) so the -ed also makes an unvoiced sound (/t/).  Words that end with a /t/ or /d/ sound, however, cannot be pronounced by adding on an additional /t/ or /d/ sound, so instead an extra syllable is added, as in the word "braided".
3. It used to be the case that the -ed ending was always pronounced as an extra syllable.  If you sing old hymns or listen to someone reading the Psalms, for example, you may observe one word that is still mid-transition in our language: blessed.  Some people pronounce it "bless-ed" and some people pronounce it "blest"!

This week's shout-out goes to my daughter, Ruth!  The entirety of #2 above was something she discovered completely independently!  We had already learned that base words that end in -t or -d cause the -ed to make it's own syllable.  But we wanted to investigate if there was anything about the base word that would predict whether the -ed would say /t/ or /d/ in other situations.

As we read through our chapter of the Bible, we made a chart of all of the -ed words we came across and whether the -ed ending made an /ed/, /t/ or /d/.  When we were done, Ruth eagerly pointed out that all of the /t/ words were unvoiced at the end of the base word, while all of the /d/ words were voiced!  We called this "Ruth's Theory" and continued to "test" it as we read.  We haven't found anything to disprove it yet.  Can you?