182: 'on' and 'off': /ɑn/ and /ɔf/

The 'cot/caught' merger and short o/aw sound revisited.


Hi again, and welcome back to Seattle Learning Academy's American English pronunciation podcast. My name is Mandy, and this is our 182nd episode.

This episode is sponsored by Pauline Midwinter of Midwinter Tuition. You can download her Android app, listen to her Elocution Podcast, or contact her for online lessons at midwintertuition.co.uk.

As always, I'll link to the related, free pronunciation lessons that are associated with this episode from this episode's transcript page. Just go to www.pronuncian.com/podcast, and click episode 182.

On and off: these two tiny little words have been a part of English since the days of Old English. They are both very high frequency words, and they happen to be nice examples of comparing the short o /ɑ/ sound and the aw sound /ɔ/ (short o /ɑ/) and (aw sound /ɔ/).

Do you hear the difference between the vowel sounds in the words on and off? On, off.

Because the American accent I use is not from an area of the country that has merged the short o /ɑ/ sound and aw sound /ɔ/ into a single sound, I do say these vowels differently. However, some parts of the United States have gone through a process called the 'cot/caught merger' by linguists. People from those places do not say these vowel sounds differently. Those individuals usually use the short o /ɑ/ sound for both sounds.

Currently, about 60% of Americans still do say the sounds differently, and so I teach my students to hear and produce the difference between the sounds so they can choose for themselves whether they would prefer to use one or both sounds in their own speech. It really is your own choice. There isn't a right or wrong answer to this one.

The short o /ɑ/ sound is pronounced as (short o /ɑ/). It is a low, back vowel. This means that the back of the tongue is kept low. You'll feel your bottom, back teeth along the sides of your tongue. In order for the tongue to remain low enough, the jaw has to drop a little bit. Because the jaw drops, the shape of the lips becomes rounded. You don't need to force your lips into a round shape for the short o /ɑ/ sound in an American accent; the lips stay relaxed, and they naturally round as the chin lowers. The sound is (short o /ɑ/).

Repeat that sound after me (short o /ɑ/).

Again, (short o /ɑ/).

Feel all of it. Feel the tension of pushing your tongue low. Feel your side, back teeth. Feel your jaw lower. Feel you lips naturally change into a rounded shape.

Say the word on, on.

Now let's move on to the aw sound /ɔ/. This sound is the optional sound of the two. If you've learned British English pronunciation, this is possibly the sound you're more comfortable with and using this sound in place of the short o /ɑ/ sound will give your speech a British flair.

The biggest difference between the sounds is the tension in the lips and even the cheeks. To create the aw sound /ɔ/ sound, we're again going to set the back of the tongue low and the jaw still drops. Now, however, you are going to actively make the lips round. The sides of the lips are brought in and the lips might stick out a little bit. When the sides of the lips are brought in, you might feel tension in your cheeks, since you're using those muscles to move the sides of your lips. The sound is (aw sound /ɔ/).

Repeat the sound after me (aw sound /ɔ/).

Again, (aw sound /ɔ/).

Let's really feel the aw sound /ɔ/. Feel the tongue pushing low as the jaw drops. Feel your back side teeth. Feel the tension in your cheeks and lips as your lips are actively made into an open circle. You may also feel your lips stick out a little bit during this sound.

Repeat the aw sound /ɔ/ after me again (aw sound /ɔ/).

Say the word off, off.

Let's practice the words on and off side-by side, and then practice a few phrases using these words.


Turn it on.
Be on time.
Hold on to it.
It's on Friday.

Turn it off.
Take a day off.
Take off your shoes.
Cut off the extra.

I hope that little practice make both of these sounds a little bit clearer for you, and a little easier to produce.

That's all for today, everyone. This has been a Seattle Learning Academy digital publication. SLA is where the world comes to learn. Thanks for listening. Bye-bye.