Phonics Investigation Challenge #2: -s and -ed

Welcome to this week's Phonics Investigation Challenge!  If you explore this challenge with your kiddos this week, be sure to leave a comment below so that we can include you in the shout-out next week!  You can watch the Scope below or read the text that follows.


Last week we explored the difference between voiced and unvoiced sounds.  This week we are going to expand on that concept by looking at two endings we sometimes add to words: -s and -ed.  We add an -s to nouns (naming words) so that they can name more than one (one cat, two cats).  We add an -s to verbs (action words) so that they can match with the subject of the sentence (We see.  Bill sees.)  We add an -ed to the end of action verbs so that they can tell about something that happened in the past.

But have you ever noticed that these sounds aren't always pronounced the same?  Say these two words out loud and think about the sound of the -s at the end.

cats
dogs

Sometimes the -s says /s/ and sometimes it says /z/!  Now try these three words and think about the sound of the -ed at the end.  (Hint: You might want to try saying the word without the -ed and then adding on the -ed to see how it changes the word.)

braided
stayed
packed

If you have studied the -ed sound much, I am sure that you have already learned that sometimes the -ed adds a syllable; it says /ed/.  But sometimes instead of adding a new syllable, it only adds the sound /d/ or /t/ to the end of the word.  Look around at words you see with -s and -ed endings.  Do you notice the different sounds those endings can make?  That leads us to our challenge for the week!

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?

Happy exploring!  As usual, be sure to share what you found in the comment so I can mention you in next week's shout-out!