The T and D consonant sounds. These two sounds are paired together because they take the
same mouth position. Tt is unvoiced, meaning, only air passes through the mouth. And dd
is voiced, meaning, uh, uh, dd, you make a noise with the vocal cords. These consonants
are stop consonants, which means there are two parts. First, a stop of the airflow, and
second, a release. The airflow is stopped by the tongue position. The tongue will come
up and the front part will touch the roof of the mouth just behind the top teeth. It
will then pull down to release the air. The teeth are together, tt, and as the air comes
out, when the tongue releases, they part, tt, dd. Let's take for example the word 'pat'.
Pat: the first part, the tongue has moved up into position, cutting off the flow of
air. Pa-tt. And the second part, the tongue releases, and the air comes through the closed
teeth. A note about the teeth position for the D. As I said, the teeth are together,
tt, and part when the air is released. This must happen for a release of the T. But the
D can actually be made without the teeth coming all the way together: dad, dad. You can see
there the teeth are not closing all the way, but you're getting a D sound by the tongue
coming up into position and pulling away. Stop consonants are sometimes pronounced without
the second part, without this release, when they come at the end of a syllable or a word.
Let's take for example the sentence 'I bet you did'. I bet, you can see the tongue has
moved up into position for the T. I bet you did. But rather than releasing air through
the teeth, the mouth simply moves into the next sound, which is the 'ew' as in 'few'
diphthong. I bet you did. I bet you did. No release. It's important to note we're not
just leaving out the sound. I bet -- the tongue is moving into position, which is cutting
off the airflow. And that stop is part of the T. I bet you did. So even though we're
not releasing to give the complete full T, the idea is still there by the tongue going
into position, cutting off the airflow. So T and D can sometimes be pronounced with the
stop and the release, and sometimes just the stop. The T has another pronunciation, it's
call the flap or tap T, and on my website in the International Phonetic Alphabet, I
use the D symbol to represent this sound because it sounds and functions, and is made just
like the D. This sound happens when the T comes between two vowel sounds. Let's take
for example, the word madder and matter. One is spelled with two D's, and one with two
T's. But they're pronounced the same: madder, matter. Let's look at them in sentences. I'm
madder than I've ever been. What's the matter? It's the same sound. The lip position of these
sounds is influenced by the sound that comes next. For example, dime, dime. You can see
the mouth is taking the shape of the first sound of the 'ai' as in 'buy' diphthong, dime,
even before the D is made. Drain, drain. Again, you can see the lips taking the position for
the R, drain, even before the D is made. Do, do, again you can see the lips taking the
circle for the 'oo' as in 'boo' vowel. Do, do. Here we see the T/D mouth position on
the right compared with the mouth at rest on the left. Here, parts of the mouth are
drawn in. The soft palate is raised for these consonant sounds. The tongue position stretches
up in the front and presses against the roof of the mouth to make the stop before releasing
the air. The position is just behind the top front teeth. Sample words: time/dime, tad/dad,
tote/dote. The last two word pairs ended with T's and D's. Did you notice that I did not
release them? Sample sentence: Tom tasted Dad's dark chocolate treats. Now you will
see this sentence up close and in slow motion, both straight on and from an angle, so you
can really study how the mouth moves making these sounds. Tom, with the T, you see the
teeth close, the tongue raised behind them. And there's the release. Tom. The lips will
close for the M, and when they open you will see the teeth are still closed for the T in
tasted. Then the ST consonant cluster, and there there's a quick ih vowel, there, before
the D, tasted. Dad's. The tongue will come up here to make the D, there will be a quick
Z before the D in dark, and you can see the lips already starting to take the form of
the R even before the teeth release. Chocolate, tongue through the teeth for the L, and then
up to make the T which is a stop here. Treats, and again you see the lips forming the R even
before the teeth release the T. And the TS sound at the end. Tom, you see the tongue
tip up behind the closed teeth, releasing into the 'ah' as in 'father'. Lips close for
the M. Tasted, tongue up to make the T, quick ih sound and then the D, tasted, Dad's. Tongue
up again to make the final D. Dad's. Dark, lips taking the form of the R. Chocolate,
tongue up for the L and then to the roof of the mouth to make the stop of the T. And treats,
where the lips form the R shape around the closed teeth. And tongue tip up to make the
final T, and S sound. Treats. That's it, and thanks so much for using Rachel's English.